applauder

noun

entity that repeatedly claps as a form of ovation for indicating approval/enjoyment/admiration

Wiktionary

noun

Etymology: Etymology tree English applaud Proto-Indo-European *-yósder. Proto-Italic *-āzijos Latin -āriusnom. Latin -āriusbor. Proto-Germanic *-ārijaz Proto-West Germanic *-ārī Old English -ere Middle English -ere English -er English applauder From applaud + -er.

One who applauds.