/ Thesaurus / B Synonyms of box number Find synonyms for: Noun1. post-office box number, PO box number, PO Box No, box number, mailing addressusage: the number of a letter box at the post office where mail is collected2. box number, mailing addressusage: a mailing address to which answers to a newspaper ad can be sentWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: sequester Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language