OS'SIFY, verb transitive [Latin os, bone, anf facio, to form.] To form bone; to change from a soft animal substance into bone, or convert into a substance of the hardness of bones. This is done by the deposition of calcarious phosphate or carbonate on the part. OS'SIFY, verb intransitive To become bone; to change from soft matter into a substance of bony hardness.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI