Definitions:

1. A liplike structure that bounds a bodily orifice. NOUN
   • The labium of certain aquatic organisms help them to filter food particles from the water.
2. Latin term that translates to "lip" in English. NOUN
   • Labium is a term used to describe a lip-like structure, particularly in biology.
3. The organ or insects which covers the mouth beneath, and serves as an under lip. NOUN
   • In insects, the labium is the lower lip and is involved in feeding and manipulating food.

Synonyms:

• labia
• lip
• lips