Gill
Part of speech: noun
Definition: A breathing organ of fish and other aquatic animals. A gill slit or gill cover. One of the radial folds on the underside of the cap of a mushroom, on the surface of which the spore-producing organs are borne. A drink measure for spirits and wine. Size varies regionally but it is about one quarter of a pint. A measuring jug holding a quarter or half a pint. A rivulet. A ravine.
Lamella
Part of speech: noun
Definition: a thin, plate-like structurethe gill of a mushroom.