Meaning

noun carnivorous or bloodsucking aquatic or terrestrial worms typically having a sucker at each end

noun a follower who hangs around a host (without benefit to the host) in hope of gain or advantage

verb draw blood

originFrom Middle English leche (“physician”), from Old English lǣċe (“doctor, physician”), from Proto-West Germanic *lākī, from Proto-Germanic *lēkijaz (“doctor”), of disputed origin, but usually thought to be connected with Proto-Celtic (compare Old Irish líaig (“doctor, physician”)); perhaps ultimately from Proto-Indo-European *leǵ- (“to collect, gather”). Cognate with Old Frisian lētza…

Etymology from Wiktionary, CC BY-SA 3.0