Source : Webster's Revised Unabridged Dictionary (1913)

Viridity \Vi*rid"i*ty\, n. [L. viriditas, fr. viridis green: cf.
   F. viridit['e]. See {Verdant}.]
   1. Greenness; verdure; the color of grass and foliage.

   2. Freshness; soundness. [Obs.] --Evelyn.

Source : WordNet®

viridity
     n : the property of being green; resembling the color of growing
         grass [syn: {green}, {greenness}]