Pronunciation: (men'tum), [key]
—pl. -taPronunciation: (-tu). [key]
1. Entomol.the medial plate of the labium in insects.
2. Bot.a chinlike protuberance formed by the sepals and the base of the column in some orchids.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.