/ Thesaurus / O Synonyms of oceanic abyss Find synonyms for: Noun1. trench, deep, oceanic abyss, natural depression, depressionusage: a long steep-sided depression in the ocean floorWordNet 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