frenulum
/ˈfriːnjʊləm
/(also fraenulum)
noun
1 Anatomy A small fold or ridge of tissue which supports or checks the motion of the part to which it is attached, in particular a fold of skin beneath the tongue, or between the lip and the gum.Unexplained injuries to protected parts of the body such as the buttocks, thighs, torso, frenulum, ears and neck are suggestive of child abuse....
- Idly running her tongue across the fraenulum, she thinks about work, and how many others in her office of twenty-six people do this.
- The frenulum is the piece of tissue connecting the tongue to the bottom.
2 Entomology (In some moths and butterflies) a bristle or row of bristles on the edge of the hindwing which keeps it in contact with the forewing.In the past, butterflies were distinguished from moths in that they flew during the day, possessed clubbed antennae, were brightly colored, and lacked a frenulum (a wing coupling mechanism found in most moths).
Origin
Early 18th century: modern Latin, diminutive of Latin frenum 'bridle'.