/ Dictionary / Index U unicorn plant: Meaning and Definition of Find definitions for: u'nicorn plant" Pronunciation: [key] a North American plant, Proboscidea (Martynia) louisianica, having creamy-white to red flowers blotched with purple, and a woody capsule with a long, curved beak. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. unicorn unicostate Related Content Daily Word Quiz: acquiesce Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language