What is the X in X-mas?
Middle English lappewinke (late 14c.), lapwyngis (early 15c.), folk etymology alteration of Old English hleapewince, probably literally "leaper-winker," from hleapan "to leap" + wince "totter, waver, move rapidly," related to wincian "to wink." Said to be so called from "the manner of its flight" [OED] "in reference to its irregular flapping manner of flight" [Barnhart], but the lapwing also flaps on the ground pretending to have a broken wing to lure egg-hunters away from its nest, which seems a more logical explanation. Its Greek name was polyplagktos "luring on deceitfully."
the name of an unclean bird, mentioned only in Lev. 11:19 and Deut. 14:18. The Hebrew name of this bird, _dukiphath_, has been generally regarded as denoting the hoope (Upupa epops), an onomatopoetic word derived from the cry of the bird, which resembles the word "hoop;" a bird not uncommon in Palestine. Others identify it with the English peewit.