SOUND Sound, a. [Compar. Sounder; superl. Soundest.] Etym: [OE. sound, AS. sund; akin to D. gezond, G. gesund, OHG. gisunt, Dan. & Sw. sund, and perhaps to L. sanus. Cf. Sane.]
1. Whole; unbroken; unharmed; free from flaw, defect, or decay; perfect of the kind; as, sound timber; sound fruit; a sound tooth; a sound ship.
2. Healthy; not diseased; not being in a morbid state; — said of body or mind; as, a sound body; a sound constitution; a sound understanding.
3. Firm; strong; safe. The brasswork here, how rich it is in beams, And how, besides, it makes the whole house sound. Chapman.
4. Free from error; correct; right; honest; true; faithful; orthodox; — said of persons; as, a sound lawyer; a sound thinker. Do not I know you a favorer Of this new seat Ye are nor sound. Shak.
5. Founded in truth or right; supported by justice; not to be overthrown on refuted; not fallacious; as, sound argument or reasoning; a sound objection; sound doctrine; sound principles. Hold fast the form of sound words, which thou hast heard of me. 2 Tim. i. 13.
6. heavy; laid on with force; as, a sound beating.
7. Undisturbed; deep; profound; as, sound sleep.
8. Founded in law; legal; valid; not defective; as, a sound title to land.
Note: Sound is sometimes used in the formation of self-explaining compounds; as, sound-headed, sound-hearted, sound-timbered, etc. Sound currency (Com.), a currency whose actual value is the same as its nominal value; a currency which does not deteriorate or depreciate or fluctuate in comparision with the standard of values.