Source : Webster's Revised Unabridged Dictionary (1913)

Lapidescent \Lap`i*des"cent\, a. [L. lapidescens, p. pr. of
   lapidescere to become stone, fr. lapis, -idis, stone: cf. F.
   lapidescent.]
   Undergoing the process of becoming stone; having the capacity
   of being converted into stone; having the quality of
   petrifying bodies.

Lapidescent \Lap"i*des"cent\, n.
   Any substance which has the quality of petrifying other
   bodies, or of converting or being converted into stone.