gadget.

A thing whose name cannot be remembered; thingamajig, doohickey.

Any device or machine, especially one whose name cannot be recalled, often either clever or complicated.

He bought a neat new gadget for shredding potatoes.

That's quite a lot of gadgets you have collected. Do you use any of them?

Any consumer electronics product.

A sequence of machine code instructions crafted as part of an exploit that attempts to divert execution to a memory location chosen by the attacker.

A technique for converting a part of one problem to an equivalent part of another problem, used in constructing reductions.

We reduce an instance of 3-SAT to an instance of bird-flock-optimization, using a gadget that converts each conjunctive Boolean clause to a group of birds.

A spring clip attached to the end of a punty in order to grasp the foot of a glass without leaving a bullion while finishing the bowl.