noun (Roman Catholic Church) one of a group of more than 100 prominent bishops in the Sacred College who advise the Pope and elect new Popes.
noun the number of elements in a mathematical set.
— synonyms: cardinal_number
noun a variable color averaging a vivid red.
— synonyms: carmine
noun crested thick-billed North American finch having bright red plumage in the male.
— synonyms: cardinal_grosbeak, Richmondena_Cardinalis, Cardinalis_cardinalis, redbird
adjective serving as an essential component.
— synonyms: central, fundamental, key, primal
adjective being or denoting a numerical quantity but not order.