Etymology: Probably < early modern German lüchsern adjective, pertaining to the lynx, < luchs lynx (see loss n.²); the word was apparently introduced as a name for the fur of the lynx; for a similar instance of an adjective becoming a noun, compare marten n.The spelling lewxerne (quot. 1662 at sense 1a), if not a misprint, is conclusive evidence in favour of this derivation. Etymologists have usually supposed the word to be an alteration of the Old French loucerve, leuserve, female lynx, a feminine of unexplained from corresponding to the masculine loup-cervier representing Latin lupus cervārius (Pliny) lynx, lit. ‘stag-hunting wolf’ (lupus wolf, cervārius adjective < cervus stag). But this hypothesis does not account for the form of the English word, nor can it be satisfactorily referred to the Old French loup cervin (as if Latin *lupus cervīnus = lupus cervarius) of which Godefroy gives one example. Possibly there may have been in Old French a confusion between loup-cervier and an adopted Germanic synonym.

Etymology: Apparently an arbitrary extension of luce n.¹, after lucern n.¹