/ Dictionary / Index M mullein: Meaning and Definition of Find definitions for: mul•lein Pronunciation: (mul'un), [key] — n. any of various plants belonging to the genus Verbascum, of the figwort family, native to the Old World, esp. V. thapsus, a tall plant with woolly leaves and a dense spike of yellow flowers. any of several similar plants. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: mullein (Thesaurus) mullah mullein pink Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language