Final answer:
A suggested and testable explanation for an event is a hypothesis, which is a preliminary step before it can be developed into a theory with extensive testing and support.
Step-by-step explanation:
A suggested and testable explanation for an event is called a hypothesis. When we encounter an observation or a set of data, a hypothesis acts as a tentative explanation that can be tested through experiments and further observation. In contrast, a theory is a well-substantiated, comprehensive explanation of an aspect of nature that has been repeatedly tested and supported by a multitude of experiments. It goes beyond a hypothesis, providing reliable predictions and explanations for a wide array of phenomena. A scientific law differs from both in that it is a description, often in mathematical terms, of a consistently observed natural phenomenon.