Source : Webster's Revised Unabridged Dictionary (1913)

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}.

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 : WordNet®

solid
     adj 1: of definite shape and volume; firm; neither liquid nor
            gaseous; "ice is water in the solid state" [ant: {liquid},
             {gaseous}]
     2: of good substantial quality; "solid comfort"; "a solid base
        hit"
     3: entirely of one substance with no holes inside; "solid
        silver"; "a solid block of wood" [ant: {hollow}]
     4: of one substance or character throughout; "solid gold"; "a
        solid color"; "carved out of solid rock"
     5: uninterrupted in space; having no gaps or breaks; "a solid
        line across the page"; "solid sheets of water"
     6: providing abundant nourishment; "a hearty meal"; "good solid
        food"; "ate a substantial breakfast" [syn: {hearty}, {satisfying},
         {substantial}]
     7: of good quality and condition; solidly built; "a solid
        foundation"; "several substantial timber buildings" [syn:
        {strong}, {substantial}]
     8: having high moral qualities; "a noble spirit"; "a solid
        citizen"; "an upstanding man"; "a worthy successor" [syn:
        {noble}, {upstanding}, {worthy}]
     9: not soft or yielding to pressure; "a firm mattress"; "the
        snow was firm underfoot"; "solid ground" [syn: {firm}]
     10: having three dimensions; "a solid object"
     11: incapable of being seen through; "solid blackness"
     12: entirely of a single color throughout; "a solid fabric"
         [syn: {self-colored}, {self-coloured}]
     13: acting together as a single undiversified whole; "a solid
         voting bloc" [syn: {unanimous}]

solid
     n 1: a substance that is solid at room temperature and pressure
     2: the state in which a substance has no tendency to flow under
        moderate stress; resists forces (such as compression) that
        tend to deform it; and retains a definite size and shape
        [syn: {solidness}]
     3: a three-dimensional shape