Definition of labium
1 : any of the folds at the margin of the vulva — compare labia majora, labia minora
2 : the lower lip of a labiate corolla
3a : a lower mouthpart of an insect that is formed by the second pair of maxillae united in the middle line
b : a liplike part of various invertebrates
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Time Traveler for labium
The first known use of labium was in 1634
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