"very large kettle or boiler," c. 1300, caudron, from Anglo-French caudrun, Old North French cauderon (Old French chauderon "cauldron, kettle"), from augmentative of Late Latin caldaria "cooking pot" (source of Spanish calderon, Italian calderone), from Latin calidarium "hot bath," from calidus "warm, hot" (from PIE root *kele- (1) "warm"). The -l- was inserted 15c. in imitation of Latin.