expression, godan verb (-ru)
bluff; act brave; put on a bold front
Used when someone pretends to be stronger, braver, or more confident than they really are, often to intimidate others or hide weakness.
彼は強そうに振る舞っているが、ただ虚勢を張っているだけだ。
He acts tough, but he's just bluffing.
交渉では、相手が虚勢を張っているのを見抜くことが大切だ。
In negotiations, it's important to see through the other party's bluff.