(ˈ)mȯ(r)|dāshəs adjective
Etymology: Latin mordac-, mordax biting, given to biting (from mordēre to bite) + English -ious — more at smart
1. : biting or given to biting
bitten in as with mordacious acid — Times Literary Supplement
2. : biting or sharp in manner or style : caustic
the lady's mordacious look showed plainly that she hated us all — Pauline R. Fadiman
• mor·da·cious·ly adverb