/ Thesaurus / F Synonyms of first in first out Find synonyms for: Noun1. first in first out, FIFO, inventory accountingusage: inventory accounting in which the oldest items (those first acquired) are assumed to be the first soldWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: dormant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language