ossify \AH-suh-fy\, intransitive verb: 1. To change into bone; to become bony. 2. To become hardened or set in a rigidly conventional pattern. 3. To change into bone; to convert from a soft tissue to a hard bony tissue. 4. To harden; to mold into a rigidly conventional pattern. One is left with the... Sign in to see full entry.