noun

1. A substance in the fundamental state of matter that retains its size and shape without need of a container (as opposed to a liquid or gas).

2. A three-dimensional figure (as opposed to a surface, an area, or a curve).

3. A favor.

   “I owe him; he did me a solid last year.”

adjective

1. (of an object or substance) That can be picked up or held, having a texture, and usually firm. Unlike a liquid or a gas.

   “Almost all metals are solid at room temperature.”

2. Large in size, quantity, or value.

3. Lacking holes, hollows or admixtures of other materials.

   “solid chocolate”

Synonyms: closed, massive, substantial

adverb

1. Solidly.

2. Without spaces or hyphens.

   “Many long-established compounds are set solid.”