/ Thesaurus / A Synonyms of atrial fibrillation Find synonyms for: Noun1. atrial fibrillation, fibrillation, cardiac arrhythmia, arrhythmiausage: fibrillation of the muscles of the atria of the heartWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: labyrinth Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language