/ Dictionary / Index A alder buckthorn: Meaning and Definition of Find definitions for: al'der buck"thorn Pronunciation: [key] a shrub or small tree, Frangula alnus, of Eurasia and northern Africa, having nonedible red fruit that turns black when ripe. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. alder alderfly Related Content Daily Word Quiz: resilient Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language