Old English liccian "to pass the tongue over the surface, lap, lick up," from Proto-Germanic *likkon (source also of Old Saxon likkon, Dutch likken, Old High German lecchon, German lecken, Gothic bi-laigon), from PIE root *leigh- "to lick."
French lécher, Italian leccare are said to be Germanic loan words. The figurative lick (one's) lips in eager anticipation is from c. 1500. Lick-ladle (1849) was an old phrase for a (human) parasite. To lick (someone or something) into shape (1610s) is in reference to the supposed ways of bears:
Beres ben brought forthe al fowle and transformyd and after that by lyckyng of the fader and the moder they ben brought in to theyr kyndely shap. ["The Pylgremage of the Sowle," 1413]