/ Dictionary / Index R red alder: Meaning and Definition of Find definitions for: red' al'der Pronunciation: [key] a tree, Alnus oregona (or A. rubra), of western North America, having smooth, mottled light gray bark and oval serrate leaves. the hard, red wood of this tree, used for making furniture. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. red admiral red alert Related Content Daily Word Quiz: clairvoyant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language