The word "caused" is the past tense of the verb "cause," which means to make something happen or bring about a particular result. When you say something "caused" another thing, you are indicating that the first thing was responsible for the occurrence of the second. For example, if heavy rain caused flooding, it means the heavy rain is the reason why flooding occurred.
The word "cause" originates from the Latin word "causa," which means "a reason" or "a case." It has evolved through Old French (cause) before becoming part of the English language.