Sound, a. [Compar. Sounder superl. Soundest.]
 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.