vitriolic UK /vɪtɹɪˈɒlɪk/US /ˌvɪt.riˈɑ.lɪk/ adjective2 •(figurative) Bitterly scathing, caustic.You vitriolic, patriotic, slam fight, bright light / Feeling pretty psyched — 1987 •(old-fashioned) Of or pertaining to vitriol; derived from or resembling vitriol. formsmore vitriolic · most vitriolic