- Anatomy Any of four folds of tissue of the female external genitalia. (noun)
- Zoology A liplike structure, such as that forming the floor of the mouth of certain invertebrates, especially insects. (noun)
- Zoology The inner margin of the opening of a gastropod shell. (noun)
- Botany One of the liplike divisions of a labiate corolla. (noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.