cardinal sin

: 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 (see college 4)

: cardinal number

: 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

: of basic importance

: very serious or grave

: an offense against religious or moral law

: an action that is or is felt to be highly reprehensible

: an often serious shortcoming : fault

: to commit a sin

: to commit an offense or fault

: the 21st letter of the Hebrew alphabet — see Alphabet Table