cardinal

noun

• 1a leading dignitary of the Roman Catholic Church. Cardinals are nominated by the pope and form the Sacred College, which elects succeeding popes (now invariably from among their own number).
• (also cardinal red) a deep scarlet color like that of a cardinal’s cassock.

• 2a New World songbird of the bunting family, with a stout bill and typically with a conspicuous crest. The male is partly or mostly red in color.

  • Family Emberizidae, subfamily Cardinalinae (the cardinal grosbeak subfamily): four genera and several species, especially the northern (or common) cardinal (Cardinalis cardinalis), the male of which is scarlet with a black face. This subfamily also includes American grosbeaks, buntings, and saltators

adjective

• of the greatest importance; fundamental:two cardinal points must be borne in mind