/ Thesaurus / P Synonyms of pessimal Find synonyms for: Adjective1. pessimal, pessimum(prenominal), worst (vs. best)usage: of an organism's environment; least favorable for survivalWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: feline Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language