/ Thesaurus / R Synonyms of rheumatoid factor Find synonyms for: Noun1. rheumatoid factor, autoantibodyusage: autoantibody that is usually present in the serum of people with rheumatoid arthritisWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language