/ Thesaurus / R Synonyms of red algae Find synonyms for: Noun1. red algae, alga, algaeusage: marine algae in which the chlorophyll is masked by a red or purplish pigment; source of agar and carrageenanWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: grimace Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language