cardinal

Of fundamental importance; crucial, pivotal.

a cardinal rule

But cardinal sins, and hollow hearts, I fear ye.

Of or relating to the cardinal directions (north, south, east and west).

a cardinal mark

Describing a “natural” number used to indicate quantity (e.g., zero, one, two, three), as opposed to an ordinal number indicating relative position.

Having a bright red color (from the color of a Catholic cardinal’s cassock).

Being one of the signs Aries, Cancer, Libra and Capricorn, associated with initiation, creation, and force.

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.

His uncle, a Cardinal, engages a Spanish youth of Moorish descent called Diego, an expert singer and player on the virginal, to unlock the secrets of the heart,[…]and cure him by the spell of his music.

Francis riled conservative cardinals with his compassion for migrants and refugees, openness towards LGBTQ+ Catholics and demands for action on the climate crisis. Among the frontrunners before the conclave began were Pietro Parolin, the Vatican’s secretary of state; Luis Antonio Tagle, a reformer from the Philippines; Péter Erdő, a traditionalist from Hungary; Robert Sarah, a cardinal from Guinea who criticised Francis’s papacy; and the moderate US cardinal Robert Prevost.

Any of various species of New-World passerine songbird in the genus Cardinalis, or in the family Cardinalidae more generally, or of similar appearance and once considered to be related to the former; so called because of their red plumage.

Breezes blowing from beds of iris quickened her breath with their perfume; she saw the tufted lilacs sway in the wind, and the streamers of mauve-tinted wistaria swinging, all a-glisten with golden bees; she saw a crimson cardinal winging through the foliage, and amorous tanagers flashing like scarlet flames athwart the pines.

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

Dark navy-blue, cardinal, golden-brown, old blue, olive, slate-gray, and telegraph-blue are the favorite solid colors seen in heavy beaver cloths […]

The cardinal red and silver grey colors were worn with great enthusiasm. In the spring-time, when the entire student body bought their new straw hats, the bands were of cardinal and grey ribbon.

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

This cardinal number is the smallest of the infinite cardinal numbers; it is the one to which Cantor has appropriated the Hebrew aleph with the suffix 0, to distinguish it from larger infinite cardinals. Thus the name of the smallest of infinite cardinals is ₀א.

Ellipsis of cardinal numeral, a word used to represent a cardinal number.

The commonest numerals in Latin, as in English, are the "cardinals" […] and the "ordinals" […].

A player on the St. Louis Cardinals team.

Smith became a Cardinal as the result of a pre-season trade.

A player on the Arizona Cardinals team.

A student or player on a sports team at the University of Louisville.