explain

(verb) make plain and comprehensible. Synonyms: explicate. Example: "He explained the laws of physics to his students."

(verb) define. Example: "The committee explained their plan for fund-raising to the dean."

(verb) serve as a reason or cause or justification of. Synonyms: excuse. Examples: "Your need to sleep late does not excuse your late arrival at work." "Her recent divorce may explain her reluctance to date again."