expression, godan verb (-ru)
be obstinate; insist stubbornly; dig in one's heels
Used when someone stubbornly refuses to change their opinion or course of action, often in the face of reason or opposition. Carries a negative nuance of unreasonable stubbornness.
彼は自分の意見に強情を張って、誰の話も聞かなかった。
He stubbornly insisted on his own opinion and wouldn't listen to anyone.
そんなに強情を張ると、後で後悔するよ。
If you dig in your heels like that, you'll regret it later.