adj. 25B6; adjective POISONOUS, toxic, deadly, harmful, dangerous, pernicious, damaging, destructive; unpleasant, nasty, disgusting, awful, dreadful, horrible, terrible; vile, revolting, foul, nauseating, appalling, offensive; malodorous, fetid, putrid; informal ghastly, horrid; poetic/literary noisome; archaic disgustful.
innocuous.