key.
An object designed to open and close a lock or to activate or deactivate something, especially a length of metal inserted into a narrow opening on the lock to which it is matched (keyed).
Meaning & usage
An object designed to open and close a lock or to activate or deactivate something, especially a length of metal inserted into a narrow opening on the lock to which it is matched (keyed).
This key is to the backdoor.
insert the key into the lock (formal); put the key in the lock (informal)
An object designed to open and close a lock or to activate or deactivate something, especially a length of metal inserted into a narrow opening on the lock to which it is matched (keyed). A card or fob that electronically signals a lock to open.
My hotel room key is a card.
The gym will give you a fob that opens the door.
An object designed to open and close a lock or to activate or deactivate something, especially a length of metal inserted into a narrow opening on the lock to which it is matched (keyed). A piece of information (e.g., a password or passphrase) used to encode or decode a message or messages.
An object designed to open and close a lock or to activate or deactivate something, especially a length of metal inserted into a narrow opening on the lock to which it is matched (keyed). A password restricting access to an IRC channel.
An object designed to open and close a lock or to activate or deactivate something, especially a length of metal inserted into a narrow opening on the lock to which it is matched (keyed). A key bump (A portion of a recreational drug in powdered form that is snorted from a key or similar small object.)
I saw him snort a key at the party.
An object designed to open and close a lock or to activate or deactivate something, especially a length of metal inserted into a narrow opening on the lock to which it is matched (keyed). Any of various tools comparable to a wrench (spanner) or driver, which have a specialized end that matches a fixture, analogously to a lock's key.
The exterminator will bring a key thingy that can open the bait boxes.
Safe-deposit boxes open with a special key.
An object designed to fit between two other objects (such as a shaft and a wheel) in a mechanism and maintain their relative orientation. A cotter pin.
An object designed to fit between two other objects (such as a shaft and a wheel) in a mechanism and maintain their relative orientation. A piece of wood used as a wedge.
An object designed to fit between two other objects (such as a shaft and a wheel) in a mechanism and maintain their relative orientation. The last board of a floor when laid down.
An object designed to fit between two other objects (such as a shaft and a wheel) in a mechanism and maintain their relative orientation. A keystone.
An object designed to fit between two other objects (such as a shaft and a wheel) in a mechanism and maintain their relative orientation. That part of the plastering which is forced through between the laths and that holds the rest in place.
An object designed to fit between two other objects (such as a shaft and a wheel) in a mechanism and maintain their relative orientation. A wooden wedge, driven sideways between a bullhead rail and a cast-iron chair, to keep the rail securely in position.
A crucial step or requirement.
Persistence is the key to solving this problem.
The key to winning that game is your strategy at the beginning.
A crucial step or requirement. An idea, theory or observation that explains, justifies or renders (something) comprehensible.
The key to his proposal is that he thinks this company is dying and needs radical change.
A crucial step or requirement. A deciding factor.
Her charm is the key to her success.
Senses relating to a guide that identifies information. A small guide explaining symbols, abbreviations or terminology, especially the legend on a map or chart.
map key
The key says that A stands for the accounting department.
Senses relating to a guide that identifies information. A guide to the correct answers of a worksheet or test.
Some students cheated by using the key.
Senses relating to a guide that identifies information. A series of logically organized groups of discriminating information which aims to allow the user to correctly identify a taxon; a taxonomic key.
Senses relating to a guide that identifies information. A value that uniquely identifies an entry in a container.
Senses relating to a guide that identifies information. In a relational database, a field used as an index into another table (not necessarily unique).
Senses relating to a set of features that modify the output of a device. One of several small, usually square buttons on a typewriter or computer keyboard, mostly corresponding to text characters.
Press the Escape key.
A key; B key, etc.
Senses relating to a set of features that modify the output of a device. In musical instruments, one of the valve levers used to select notes, such as a lever opening a hole on a woodwind.
piano key
Senses relating to a set of features that modify the output of a device. In instruments with a keyboard such as an organ or piano, one of the levers, or especially the exposed front end of it, which are depressed to cause a particular sound or note to be produced.
A scale or group of pitches constituting the basis of a musical composition.
the key of B-flat major
A scale or group of pitches constituting the basis of a musical composition. The lowest note of a scale; keynote.
A scale or group of pitches constituting the basis of a musical composition. In musical theory, the total melodic and harmonic relations, which exist between the tones of an ideal scale, major or minor; tonality.
A scale or group of pitches constituting the basis of a musical composition. In musical theory and notation, the tonality centering in a given tone, or the several tones taken collectively, of a given scale, major or minor.
A scale or group of pitches constituting the basis of a musical composition. In musical notation, a sign at the head of a staff indicating the musical key.
A scale or group of pitches constituting the basis of a musical composition. The general pitch or tone of a sentence or utterance.
A scale or group of pitches constituting the basis of a musical composition. The general pitch or tone of a sentence or utterance. A modification of an advertisement so as to target a particular group or demographic.
Senses of items with visual similarity to a key or group of keys on a keyring. An item of decor shaped like a key.
Senses of items with visual similarity to a key or group of keys on a keyring. An indehiscent, one-seeded fruit furnished with a wing, such as the fruit of the ash and maple; a samara.
Senses of items with visual similarity to a key or group of keys on a keyring. The free-throw lane together with the circle surrounding the free-throw line, the free-throw lane having formerly been narrower, giving the area the shape of a skeleton key hole.
He shoots from the top of the key.
Senses of items with visual similarity to a key or group of keys on a keyring. The thirty-third card of the Lenormand deck, which features an image of a key.
Senses related to colors. The overall color tone of a painting or other visual art, with a high key indicating generally light colors and a low key indicating generally dark colors.
Senses related to colors. The black ink layer, especially in relation to the three color layers of cyan, magenta, and yellow. See also CMYK.
Senses related to colors. A color to be masked or made transparent.
A manual electrical switching device primarily used for the transmission of Morse code.
The degree of roughness, or the ability of a surface to retain an applied liquid, such as paint or glue.
The door panel should be sanded down carefully to provide a good key for the new paint.
Where this word comes from
From Middle English keye, kaye, keiȝe, from Old English cǣġ (“key, solution, experiment”) (whence also Scots key and kay (“key”)), from Anglo-Frisian Proto-West Germanic *kaiju, of uncertain origin. The only sure cognates are Saterland Frisian Koai (“key”), West Frisian kaai (“key”), and North Frisian kai, koie (“key”). Possibly from Proto-Germanic *kēgaz, *kēguz (“stake, post, pole”), from Proto-Indo-European *ǵogʰ-, *ǵegʰ-, *ǵegʰn- (“branch, stake, bush”), which would make it cognate with Middle Low German kāk (“whipping post, pillory”), and perhaps to Middle Dutch keige (“javelin, spear”) and Middle Low German keie, keige (“spear”). For the semantic development, note that medieval keys were simply long poles (ending in a hook) with which a crossbar obstructing a door from the inside could be removed from the outside, by lifting it through a hole in the door. Liberman has noted, however, "The original meaning of *kaig-jo- was presumably '*pin with a twisted end.' Words with the root *kai- followed by a consonant meaning 'crooked, bent; twisted' are common only in the North Germanic languages."
Indispensable, supremely important.
He is the key player on his soccer team.
Important, salient.
She makes several key points.
Where this word comes from
From Middle English keye, kaye, keiȝe, from Old English cǣġ (“key, solution, experiment”) (whence also Scots key and kay (“key”)), from Anglo-Frisian Proto-West Germanic *kaiju, of uncertain origin. The only sure cognates are Saterland Frisian Koai (“key”), West Frisian kaai (“key”), and North Frisian kai, koie (“key”). Possibly from Proto-Germanic *kēgaz, *kēguz (“stake, post, pole”), from Proto-Indo-European *ǵogʰ-, *ǵegʰ-, *ǵegʰn- (“branch, stake, bush”), which would make it cognate with Middle Low German kāk (“whipping post, pillory”), and perhaps to Middle Dutch keige (“javelin, spear”) and Middle Low German keie, keige (“spear”). For the semantic development, note that medieval keys were simply long poles (ending in a hook) with which a crossbar obstructing a door from the inside could be removed from the outside, by lifting it through a hole in the door. Liberman has noted, however, "The original meaning of *kaig-jo- was presumably '*pin with a twisted end.' Words with the root *kai- followed by a consonant meaning 'crooked, bent; twisted' are common only in the North Germanic languages."
To fit (a lock) with a key.
To fit (pieces of a mechanical assembly) with a key to maintain the orientation between them.
To mark or indicate with a symbol indicating membership in a class.
To depress (a telegraph key).
To operate (the transmitter switch of a two-way radio).
(more usually to key in) To enter (information) by typing on a keyboard or keypad.
To vandalize (a car, etc.) by scratching with an implement such as a key.
He keyed the car that had taken his parking spot.
To link (as one might do with a key or legend).
To be identified as a certain taxon when using a key.
To modify (an advertisement) so as to target a particular group or demographic.
To attune to; to set at; to pitch.
To fasten or secure firmly; to fasten or tighten with keys or wedges.
To prepare for plastering by adding the key (that part of the plastering which is forced through between the laths and holds the rest in place).
To provide an arch with a keystone.
Clipping of chromakey.
Where this word comes from
From Middle English keye, kaye, keiȝe, from Old English cǣġ (“key, solution, experiment”) (whence also Scots key and kay (“key”)), from Anglo-Frisian Proto-West Germanic *kaiju, of uncertain origin. The only sure cognates are Saterland Frisian Koai (“key”), West Frisian kaai (“key”), and North Frisian kai, koie (“key”). Possibly from Proto-Germanic *kēgaz, *kēguz (“stake, post, pole”), from Proto-Indo-European *ǵogʰ-, *ǵegʰ-, *ǵegʰn- (“branch, stake, bush”), which would make it cognate with Middle Low German kāk (“whipping post, pillory”), and perhaps to Middle Dutch keige (“javelin, spear”) and Middle Low German keie, keige (“spear”). For the semantic development, note that medieval keys were simply long poles (ending in a hook) with which a crossbar obstructing a door from the inside could be removed from the outside, by lifting it through a hole in the door. Liberman has noted, however, "The original meaning of *kaig-jo- was presumably '*pin with a twisted end.' Words with the root *kai- followed by a consonant meaning 'crooked, bent; twisted' are common only in the North Germanic languages."
One of a string of small islands.
the Florida Keys
Where this word comes from
Variant of cay, from Spanish cayo, from Taíno cayo (“small island”)
A kilogram, especially of a recreational drug.
Where this word comes from
Clipping of kilogram or kilo.
A key position player (a tall forward or defender).
Where this word comes from
Clipping of key position.
Alternative form of quay.
Try it on your idea.
key has 3 characters. Say it out loud, try it alongside a description of your project, and see whether its meaning fits what you want to create.
These are naming prompts. Meanings and pronunciation can vary; existing brand and domain uses have not been checked.
Explore the name generatorA word with a source.
Definitions, grammatical labels, IPA, etymology and examples: Wiktionary contributors, extracted by Kaikki / Wiktextract. Adapted under CC BY-SA 4.0. Selected fields and authored examples are shown; third-party quotations and audio are omitted. See contributor history.
Last enriched 2026-09-10. Definitions are in English. Romanizations are shown when supplied by the source; syllable estimates are omitted for unsupported scripts.