When a cruiser becomes an aircraft carrier

At what point is a cruiser officially an aircraft carrier?

When its embarked aircraft become its primary means of offense and defense rather than a supporting capability.

The answer defines a carrier by the role of its embarked or parasite craft rather than by hull shape or the continued presence of shipboard weapons. If fighters are expected to intercept threats at distance and the air group is the preferred striking arm, the ship functions as a carrier. If onboard guns, missiles, or other systems remain the primary means of fighting, it is still a cruiser or a hybrid. The distinction focuses classification on operational doctrine and combat function.