SOL'ID, adjective [L, solidus; from the sense to setting or pressure, and hence allied to Latin solum, Eng. sill.]

1. Hard; firm; compact; having its constituent particles so close or dense as to resist the impression or penetration of other bodies. Hence solid bodies are not penetrable, not are the parts moveable and easily displaced like those of fluids. solid is opposed to fluid and liquid.

2. Not hollow; full of matter; as a solid globe or cone, as distinguished from a hollow one.

3. Having all the gemetrical dimensions; cubic; as, a solid foot contains 1728 solid inhes. [In this sense, cubic is not generally used.]

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

5. Sound; not weakly; as a solid constitution of body. [Sound is more generally used.]

6. Real; sound; valid; true; just; not empty or fallacious. Wise men seek solid reasons for their opinions.

7. Grave; profound; not light, trifling or superficial. These wanting wit, affect gravity, and go by the name of solid men.

8. In botany, of a fleshy, uniform, undivided substance, as a bulb or root; not spungy or hollow within, as a stem.

A solid FOOT, contains 1728 solid inches, weighing 1000 ounces of rain water.

SOLID ANGLE, an angle formed by three or more plain angles meeting in a point.

SOLID SQUARE, in military language, is a square body of troops; a body in which the ranks and files are equal.

SO'LID, noun A firm compact body. In anatomy and medical science, the bones, flesh and vessls of animal bodies are called solids, in distinction from the blood, chyle and other fluids.