/ Thesaurus / P Synonyms of per diem Find synonyms for: Noun1. per diem, allowanceusage: a daily allowance for living expenses (especially while traveling in connection with your job)Adverb1. per diem, by the dayusage: one every day; "we'll save 100 man-hours per diem"WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: frugal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language