Solid \Sol"id\, a. [L. solidus, probably akin to sollus whole, entire, Gr. ???: cf. F. solide. Cf. Consolidate,Soda, Solder, Soldier, Solemn.]

1. Having the constituent parts so compact, or so firmly adhering, as to resist the impression or penetration of other bodies; having a fixed form; hard; firm; compact; -- opposed to fluid and liquid or to plastic, like clay, or to incompact, like sand.

2. Not hollow; full of matter; as, a solid globe or cone, as distinguished from a hollow one; not spongy; dense; hence, sometimes, heavy.

3. (Arith.) Having all the geometrical dimensions; cubic; as, a solid foot contains 1,728 solid inches.

Note: In this sense, cubics now generally used.

4. Firm; compact; strong; stable; unyielding; as, a solid pier; a solid pile; a solid wall.

5. Applied to a compound word whose parts are closely united and form an unbroken word; -- opposed to hyphened.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Solid \Sol"id\, n.

1. A substance that is held in a fixed form by cohesion among its particles; a substance not fluid.

2. (Geom.) A magnitude which has length, breadth, and thickness; a part of space bounded on all sides.

Solid of revolution. (Geom.) See Revolution, n., 5.

Source: Webster's Revised Unabridged Dictionary (1913)