One who is Catholic from the cradle (circular definitions are always true, albeit superfluous). Catholics baptize infants, and thereby they are Catholics from infancy. One can be cradle Orthodox, or cradle Lutheran for the same reason, but not cradle Baptists or Nazorene, since these groups are Anabaptist in nature, i.e. they confere baptism after the age of reason.
Make sense?
In Christ,
Adam