/ Thesaurus / S Synonyms of soil pipe Find synonyms for: Noun1. soil pipe, drain, drainpipe, waste pipeusage: drain that conveys liquid waste from toilets, etc.WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: nefarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language