What is the X in X-mas?
late 14c., from Anglo-French vultur, Old French voultour, from Latin vultur, earlier voltur, perhaps related to vellere "to pluck, to tear." Figurative sense is recorded from 1580s.
(1.) Heb. da'ah (Lev. 11:14). In the parallel passage (Deut. 14:13) the Hebrew word used is _ra'ah_, rendered "glede;" LXX., "gups;" Vulg., "milvus." A species of ravenous bird, distinguished for its rapid flight. "When used without the epithet 'red,' the name is commonly confined to the black kite. The habits of the bird bear out the allusion in Isa. 34:15, for it is, excepting during the winter three months, so numerous everywhere in Palestine as to be almost gregarious." (See EAGLE.) (2.) In Job 28:7 the Heb. 'ayyah is thus rendered. The word denotes a clamorous and a keen-sighted bird of prey. In Lev. 11:14 and Deut. 14:13 it is rendered "kite" (q.v.).