1. cardinal number the number of elements in a mathematical set
  2. ordinal number the number designating place in an ordered sequence
  3. Cardinal Newman English prelate and theologian who (with John Keble and Edward Pusey) founded the Oxford movement; Newman later turned to Roman Catholicism and became a cardinal (1801-1890)
  4. rational number an integer or the quotient of two integers
  5. irrational number a real number that cannot be expressed as a rational number
  6. cardinal flower North American lobelia having brilliant red flowers
  7. Brinell number measure of the hardness of a material
  8. cardinal tetra small bright red and blue aquarium fish from streams in Brazil and Colombia
  9. natural number the number 1 and any other number obtained by adding 1 to it repeatedly
  10. real number any rational or irrational number
  11. call number a mark consisting of characters written on a book
  12. baryon number a number equal to the difference between the number of baryons and the number of antibaryons in any subatomic structure; it is conserved in all types of particle interactions
  13. cardinal a vivid red color
  14. cardinalate cardinals collectively
  15. cardinal virtue one of the seven preeminent virtues
  16. Martin Luther German theologian who led the Reformation
  17. cardiac murmur an abnormal sound of the heart
  18. cardinal vein any of the major venous channels in primitive adult vertebrates and in embryos of higher vertebrates
  19. cardinalship the office of cardinal
  20. cardinalfish small red fishes of coral reefs and inshore tropical waters