/ Dictionary / Index L labetalol: Meaning and Definition of Find definitions for: la•bet•a•lol Pronunciation: (lu-bet'u-lôl", -lol"), [key] — n. Pharm. an alpha- and beta-adrenergic blocking agent, CHNO, used in the treatment of hypertension. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: labetalol (Thesaurus) labellum labia 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