1To firmly state and insist on one's opinion; can also refer to the content of that opinion itself.
彼は最後まで自分の主張を曲げなかった。
He never budged from his position until the end.
その記事の主張には説得力がある。
The argument made in that article is convincing.
会議では各部署がそれぞれの主張をした。
At the meeting, each department made its own case.
子どもも自分の意見を主張できるようになるべきだ。
Children should also become able to assert their own opinions.