ossifying
Webster's Dictionary (GCIDE)
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]
Ossifying \Os"si*fy`ing\, a. (Physiol.) Changing into bone; becoming bone; as, the ossifying process. [1913 Webster]