Cauldron
Middle English: from Anglo-Norman French caudron, based on Latin caldarium, calidarium ‘cooking-pot’, from calidus ‘hot’.
wiktionary
From Middle English caudron, borrowed from Old Northern French caudron (Old French chaudron, chauderon), itself from a derivative of Latin calidārium, caldārium(“cooking-pot”), from calidus(“hot”). Spelling later Latinized by having an l inserted. See chowder, caldera.
etymonline
cauldron (n.)
"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.