What does labium mean?
Labium is a formal term for a lip or a lip-like structure. Its best-known use is in human anatomy, where the labia are the folds of tissue at the external opening of the vagina; the singular labium refers to either fold. The word also has specialized uses in zoology, botany, and mycology for structures resembling a lip. In botany, a flower’s labellum is a modified petal, while the separate term labium may describe a lip-like margin or flap. In insects such as dragonflies and butterflies, the labium is a lower mouthpart formed from paired appendages and used in feeding. Because “labium” is a technical term, ordinary speakers normally use “lip” or a more specific anatomical expression instead. Its Latin ancestry connects it with words such as “labial” and “labiate,” all referring to lips or lip-like features.
nounA lip or lip-like anatomical structure. The term is used especially for the outer fold of the vulva and for various structures in animals, plants, and fungi.
- An outer lip-like fold, especially one of the folds forming the vulva.
- A lip-like or margin-like structure in an animal, plant, or fungus.
- The lower lip of an insect, as in a butterfly or dragonfly.
"The lower labium of the flower encloses the stamens and pistil."
"The labium is the larger, outer fold of the vulva."
"In dragonflies, the labium is a modified pair of mouthparts used to grasp prey."
The standard plural is labia, referring to the lip-like folds collectively. In anatomical usage, the singular labium identifies either individual fold.
"The labia vary naturally in color, size, and symmetry."
In botany, the “lip” of a flower is called a labellum, while the same Latin root gives us labium for other lip-like structures.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does labium come from?
Labium comes from Latin labium, meaning “lip,” a term that was also used for related anatomical structures. Latin derivatives include labialis, the source of English “labial,” and related terms connected with lips. The English form entered scientific usage through anatomical and natural-history descriptions of lip-like structures.
Related word forms
How labium is actually used
This is a formal anatomical or botanical term rather than an everyday word. In human anatomy, it is used chiefly in the singular to name either side of the external vulva, although plural forms are common in clinical contexts.
Easily confused with labium
Labium is a noun referring to a particular lip-like anatomical structure, whereas labial is chiefly an adjective meaning related to the lips or located near them.