/ Thesaurus / M Synonyms of master at arms Find synonyms for: Noun1. master-at-arms, petty officer, PO, P.O.usage: the senior petty officer; responsible for discipline aboard shipWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: abominable Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language