'plaudit' originates from Latin, specifically the word 'plaudere', where 'plaud-' meant 'to clap' or 'to strike (with the hand)'

'plaudit' changed from the Latin participle forms (related to 'plaudere' and 'plauditus') and entered English usage (18th century) as 'plaudit' meaning 'applause' or 'an expression of approval'

Initially, it meant 'a clap' or the act of clapping (and by extension 'he/she applauds'), but over time it evolved into its current meaning of 'an expression of approval; praise or acclaim'