An explanation of a natural event that is supported by a large body of evidence is called

An explanation of a natural event that is supported by a large body of evidence is called a scientific theory.

Explanation:

When a natural event, for example, that of continental drifting, is explained using pieces of evidence that are logical enough to prove the occurrence of the event in the way it is being explained, then the explanation can be called a scientific theory, for it is based on facts, not mere assumptions.

it is called a stimulus.