/ Thesaurus / S Synonyms of silt up Find synonyms for: Verb1. silt up, silt, clog, choke off, clog up, back up, congest, choke, foulusage: become chocked with silt; "The river silted up"WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: neologism Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language