/ Dictionary / Index L labium: Meaning and Definition of Find definitions for: la•bi•um Pronunciation: (lā'bē-um), [key] — pl. -bi•a a lip or liplike part. a lip or lip-shaped structure or part. any of the folds of skin bordering the vulva. the lower lip of a bilabiate corolla. the posterior, unpaired member of the mouthparts of an insect, formed by the united second maxillae. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: labium (Thesaurus) labiovelarize lablab Related Content Daily Word Quiz: rustic Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language