cardin- +

1. In the Roman Catholic Church, one of the group of clergy, next in rank to the pope, who elect the pope from their own group and act as his advisers.
2. A deep strong red color, like that of the robes of a cardinal.
3. A crested finch, the male of which has bright red plumage with a black face; native to, North America. The bird's Latin name is Cardinalis cardinalis.
4. In mathematics, a cardinal number.
5. A woman's short cape with a hood, originally scarlet in color, which was worn in the 17th and 18th centuries.
6. Etymology: from about 1125, "one of the ecclesiastical princes who constitute the sacred college"; from Latin cardinalis, "principal, chief, essential"; from cardo, cardinis, "that on which something turns or depends"; originally "door hinge".

Ecclesiastical usage began for the presbyters of the chief, or cardinal, churches of Rome.

Cardinal numbers, "chief, principal"; are the primitive "one, two, three," etc. as opposed to ordinal numbers "first, second, third," etc.

Cardinal points are "north, south, east, west". The cardinal virtues were divided into natural (justice prudence, temperance, fortitude) and theological (faith, hope, charity).

The North American songbird (Cardinalis virginianus) was named because of its resemblance to the red robes of the cardinals.

The rank or office of a Roman Catholic cardinal.

A reference to a set, the cardinal number indicating the number of elements in the set.

1. A synod of cardinals.
2. A college of cardinals.

The matter is on a door hinge.

Another translation is "We are facing a crisis."

A division of brachiopods including those which have a calcareous shell furnished with a hinge and hinge teeth. Terebratula and Spirifer are examples.