/ Thesaurus / C Synonyms of clog up Find synonyms for: Verb1. clog, choke off, clog up, back up, congest, choke, foul, obstruct, obturate, impede, occlude, jam, block, close upusage: become or cause to become obstructed; "The leaves clog our drains in the Fall"; "The water pipe is backed up"WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: profiterole Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language