| n. | 1. | (Zool.) The front median plate of the labium in insects. See Labium. |
| Noun | 1. | mentum - a projection like a chin formed by the sepals and base of the column in some orchids |
| 2. | mentum - the protruding part of the lower jaw Synonyms: chin | |
| 3. | mentum - a projection below the mouth of certain mollusks that resembles a chin |