Cal ‧ vin, John /ˈkælvən, ˈkælvɪn/ BrE AmE
(1509–64) a French ↑ Protestant leader and ↑ theologian (=someone who studies religion and religious beliefs) , whose ideas strongly influenced the ↑ reformation (=the time when many Christians left the Catholic religion and started the Protestant religion) ⇨ ↑ Calvinism