Despite her quiet demeanor at work, she becomes remarkably vivacious when discussing her passions.

vivacious 来自拉丁语 vivax（充满活力的），由词根 viv-（生命、活力）和形容词后缀 -acious（倾向于...的）组成，意思是"充满活力的、活泼热情的"，常用来形容人性格开朗、精力充沛的特质。