/ Thesaurus / B Synonyms of blood serum Find synonyms for: Noun1. serum, blood serum, liquid body substance, bodily fluid, body fluid, humor, humourusage: an amber, watery fluid, rich in proteins, that separates out when blood coagulatesWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: lyre Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language