From earlier *lākis via palatalization, from Proto-Baltic *talk-, *tlāk- (with reduction of the “difficult” cluster tl to l), from Proto-Indo-European *tel-k-, *tl-ek- (“to push, to hit, to kick, to trample”). The original meaning of this word was therefore “trampler,” “stomper,” “pounder,” showing that it was a descriptive term that replaced (probably for taboo reasons) an earlier word for “bear” (cf. Proto-Indo-European *h₂ŕ̥tḱos, whence Latin ursus, Ancient Greek ἄρκτος (árktos), Sanskrit ऋक्ष (ṛ́kṣa)), which left no traces in Baltic. (An earlier theory, which related lācis to the verb lakt “to drink,” i.e., the “(honey) drinker,” is not reconcilable with the Old Prussian cognate.) Cognates include Lithuanian lokỹs, Old Prussian clokis (klokis) (< *tlokis; cf. place names like Tlokumpelk (“bear swamp”)), Sudovian łukas. Compare Russian топтыгин (toptygin, “bear, lit. trampler, stomper”).