mentum

[ men-tuh m ]

/ ˈmɛn təm /

Entomology. the medial plate of the labium in insects.

Botany. a chinlike protuberance formed by the sepals and the base of the column in some orchids.

Words nearby mentum

1685–95; < New Latin, Latin mentum chin, akin to mouth

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Rostrum and mentum absent; mouth represented by a minute orifice between the second pair of feet.
An Account of the Insects Noxious to Agriculture and Plants in New Zealand|W. M. Maskell
Gulo-mental: includes the region covered by the gulag and mentum.
Explanation of Terms Used in Entomology|John. B. Smith
Subglossa: in Odonata; a sclerite between the two halves of the mentum (Graber): is really the true mentum.
Explanation of Terms Used in Entomology|John. B. Smith
Anthobian: feeding on flowers; applied to certain lamellicorn Coleoptera in which the labium extends beyond the mentum.
Explanation of Terms Used in Entomology|John. B. Smith

But the -mentum is a mere termination, and has nothing to do with mens at all.
Encyclopaedia Britannica, 11th Edition, Volume 15, Slice 5|Various

mentum

[ mĕn′təm ]

The chin.