1. [noun] (uncountable) The state or quality of being sound.
2. [noun] (countable) The result or product of being sound.
3. [noun] (logic) The property (of an argument) of not only being valid, but also of having true premises.
4. [noun] (logic) The property of a logical theory that whenever a wff is a theorem then it must also be valid. Symbolically, letting T represent a theory within logic L, this can be represented as the property that whenever ( T vdash phi) is true, then ( T vDash phi) must also be true, for any wff ? of logic L.
5. [noun] A state or condition free from damage or decay.
6. [noun] The quality of being prudent and sensible.
7. [noun] The muscle tone of healthy tissue; 'his muscular firmness'.
