The Collaborative International Dictionary of English v.0.48:

Lapidify \La*pid"i*fy\, v. i.
   To become stone or stony.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Lapidify \La*pid"i*fy\, v. t. [imp. & p. p. Lapidified; p. pr.
   & vb. n. Lapidifying.] [Cf. f. lapidifier. See Lapidific,
   and -fy.]
   To convert into stone or stony material; to petrify.
   [1913 Webster]

WordNet (r) 3.0 (2006):

lapidify
    v 1: change into stone; "the wood petrified with time" [syn:
         lapidify, petrify]