/ Thesaurus / Q Synonyms of quadrillionth Find synonyms for: Noun1. one-quadrillionth, quadrillionth, common fraction, simple fractionusage: one part in a quadrillion equal partsAdjective1. quadrillionth, ordinal (vs. cardinal)usage: the ordinal number of one quadrillion in counting orderWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: ontiguous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language