/ Dictionary / Index C cardinal tetra: Meaning and Definition of Find definitions for: car'dinal tet'ra Pronunciation: [key] a small, brilliantly colored red and blue characin fish, Paracheirodon axelrodi, native to tropical forest streams in Brazil and Colombia: a popular aquarium fish. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. cardinal system cardinal trait Related Content Daily Word Quiz: denizen Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language