Added 10 October 2026 imperturbability noun Categories: FeelingsRare Words noun ! Definition from Wiktionary (CC BY-SA). More about imperturbability at Wordnik → Where our words come from → A state of calm, unruffled self-assurance; aplomb, composure. Related Words: imperturbablenesscoolnessphlegmequanimityunrufflednessself-possessionplacidityæquanimityeven-mindednessbalancesangfroidunperturbedness Back to today's word