cardinal

/ˈkärd-nəl/

Middle English, from Anglo-French, from Medieval Latin cardinalis, from Late Latin cardinalis, adjective seecardinal

noun

  1. a high ecclesiastical official of the Roman Catholic Church who ranks next below the pope and is appointed by him to assist him as a member of the college of cardinals

  2. cardinal number —usually used in plural

  3. a crested finch (Cardinalis cardinalis of the family Cardinalidae) of the eastern U.S. and adjacent Canada, the southwestern U.S., and Mexico to Belize which has a black face and heavy red bill in both sexes and is nearly completely red in the male

adjective

  1. of basic importance

  2. very serious or grave

a cardinal principle

essential fundamental vital cardinal mean so important as to be indispensable. essential implies belonging to the very nature of a thing and therefore being incapable of removal without destroying the thing itself or its character. fundamental applies to something that is a foundation without which an entire system or complex whole would collapse.

noun

  1. a North American lobelia (Lobelia cardinalis) that bears a spike of brilliant red flowers