Source : Webster's Revised Unabridged Dictionary (1913)

Sanity \San"i*ty\, n. [L. sanitas, from sanus sound, healthy.
   See {Sane}.]
   The condition or quality of being sane; soundness of health
   of body or mind, especially of the mind; saneness.

Source : WordNet®

sanity
     n : normal or sound powers of mind [syn: {saneness}] [ant: {insanity}]