Synonyms for Mordacious (same or very similar meaning)
WordNet sense 1 (capable of wounding):
barbed, biting, pungent, nippingWordNet sense 2 (expressing or expressive of ridicule that wounds):
sarcasticWordNet sense 3 (involving or causing danger or risk; liable to hurt or harm):
dangerous, unsafeFrom the ODE community, based on WordNetadd/edit