/ Dictionary / Index A arborous: Meaning and Definition of Find definitions for: ar•bor•ous Pronunciation: (är'bur-us), [key] — adj. of or pertaining to trees. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: arborous (Thesaurus) arborization arbor vitae Related Content Daily Word Quiz: simian Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language