na-adjective, noun
proper; reasonable; natural (outcome)
Describes a result, choice, or progression that is appropriate, expected, or in line with reason and common sense. Often used for outcomes that follow logically from circumstances.
彼が選ばれたのは順当な結果だ。
It's a natural outcome that he was chosen.
順当に考えれば、次の社長は彼だろう。
Reasonably speaking, he will probably be the next president.