A conjunction used to qualify or contrast what was just said—similar to 'but then' or 'however'.
彼は来るだろう。もっとも、遅れるかもしれないが。
He will probably come. That said, he might be late.
その意見は一理ある。もっとも全てを鵜呑みにするわけにはいかない。
That opinion has some merit. However, we can't take everything at face value.
彼女は有能だ。もっとも経験は浅い。
She is competent. That said, she has little experience.
Reasonable or natural; used to say that something is fair or justified.
それはもっともな意見だ。
That's a reasonable opinion.
彼が怒るのももっともだ。
It's only natural that he's angry.
もっともな理由があれば、説得しやすい。
If there's a good reason, it's easier to persuade someone.