/ Thesaurus / A Synonyms of arbor day Find synonyms for: Noun1. Arbor Day, dayusage: a day designated for planting treesWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: eccentric Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language