cardinal in Italian

Of fundamental importance; crucial, pivotal.

(Roman Catholic) One of the officials appointed by the pope in the Roman Catholic Church, ranking only below the pope, equal to the patriarchs, constituting the special college which elects the pope.

A deep red color, somewhat less vivid than scarlet, the traditional colour of a Catholic cardinal's cassock. (same as cardinal red)

(math) Ellipsis of cardinal number, a number indicating quantity, or the size of a set (e.g., 0, 1, 2, 3). (See Cardinal_number.)