頦; 下顎
Mentum \Men"tum\, n. [L., chin.] (Zo["o]l.) The front median plate of the labium in insects. See {Labium}.
mentum n 1: a projection like a chin formed by the sepals and base of the column in some orchids 2: the protruding part of the lower jaw [syn: {chin}] 3: a projection below the mouth of certain mollusks that resembles a chin