- 1an aquatic or terrestrial annelid worm with suckers at both ends. Many species are bloodsucking parasites, especially of vertebrates, and others are predators.
- Class Hirudinea: many species. See also medicinal leech
verb[no object] (leech on/off)
Old English lǣce, lȳce; related to Middle Dutch lake, lieke
Do not confuse leech with leach. Leech means 'a bloodsucking worm' or 'exploit someone' (he’s leeching off the abilities of others), whereas leach means 'remove a substance from soil by the action of water' (the nutrient is quickly leached away).