Which term refers to an overflow of emotions that is heartfelt?

The term that refers to an overflow of emotions that is heartfelt is "effusive." This word describes a strong, unrestrained expression of feelings, often characterized by enthusiasm or gratitude. When someone is effusive, they share their emotions openly and abundantly, often conveying a sense of warmth and sincerity. This makes it particularly suitable for describing heartfelt expressions of love, joy, or gratitude.

In contrast, the other terms do not convey the same meaning. "A priori" relates to knowledge that is independent of experience, often used in philosophical discussions. "Plaudits" refers to statements of praise or approval, lacking the emotional quality of overflow. "Prevarication" means to speak or act in an evasive way, which is unrelated to heartfelt emotions. Thus, "effusive" stands out as the best choice for describing an overflow of heartfelt emotions.