/ Thesaurus / R Synonyms of reef knot Find synonyms for: Noun1. reef knot, flat knot, square knotusage: a square knot used in a reef lineWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: penurious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language