The Collaborative International Dictionary of English v.0.48:

Ossify \Os"si*fy\, v. t. [imp. & p. p. Ossified; p. pr. & vb.
   n. Ossifying.] [L. os, ossis, bone + -fy: cf. F. ossifier.
   See Osseous.]
   1. (Physiol.) To form into bone; to change from a soft animal
      substance into bone, as by the deposition of lime salts.
      [1913 Webster]

   2. (Fig.): To harden; as, to ossify the heart. --Ruskin.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Ossified \Os"si*fied\, a.
   Changed to bone or something resembling bone; hardened by
   deposits of mineral matter of any kind; -- said of tissues.
   [1913 Webster]

WordNet (r) 3.0 (2006):

ossified
    adj 1: set in a rigidly conventional pattern of behavior,
           habits, or beliefs; "obsolete fossilized ways"; "an
           ossified bureaucratic system" [syn: fossilized,
           fossilised, ossified]

Moby Thesaurus II by Grady Ward, 1.0:

33 Moby Thesaurus words for "ossified":
   backed, bone, bony, calcified, callous, calloused, case-hardened,
   crusted, crusty, crystallized, fossilized, granulated, hardened,
   hornified, incrusted, indurate, indurated, lapidified, osseous,
   ossicular, ossiferous, osteal, petrified, reinforced, rigidified,
   sclerotic, set, solidified, steeled, stiffened, strengthened,
   toughened, vitrified