concrete.

Real, actual, tangible.

Fuzzy videotapes and distorted sound recordings are not concrete evidence that Bigfoot exists.

Once arrested, I realized that handcuffs are concrete, even if my concept of what is legal wasn't.

Real, actual, tangible. Analogous to the categories of algebraic objects which category theory was created to generalize, in the sense of having objects which can be thought of as sets equipped with some additional structure. Formally, equipped with a faithful functor to the category of sets.

Real, actual, tangible. Equipped with a faithful functor to X (called a base category), in which case C is called a concrete category over X.

Being or applying to actual things, rather than abstract qualities or categories.

Particular, specific, rather than general.

While everyone else offered thoughts and prayers, she made a concrete proposal to help.

concrete ideas

Made of concrete (building material).

The office building had concrete flower boxes out front.

Made up of separate parts; composite.

Not liquid or fluid; solid.

A building material created by mixing cement, water, and aggregate such as gravel and sand.

Various types of concrete have been used in the construction of this highway.

A building material created by mixing cement, water, and aggregate such as gravel and sand. Such a material whose cement is Portland cement or a similar limestone derivative.

The sidewalk was made of concrete that had been poured in large slabs.

A term designating both a quality and the subject in which it exists; a concrete term.

A dessert of frozen custard with various toppings.

An extract of herbal materials that has a semi-solid consistency, especially when such materials are partly aromatic.

Sugar boiled down from cane juice to a solid mass.

Any solid mass formed by the coalescence of separate particles; a compound substance, a concretion.

To cover with or encase in concrete (building material).

I hate grass, so I concreted over my lawn.

To solidify: to change from being abstract to being concrete (actual, real).

To unite or coalesce into a solid mass.