1to behave; to conduct oneself; to act in a certain manner (attitude, manners).
パーティーでは礼儀正しく振舞ってください。
Please behave politely at the party.
彼はいつも紳士的に振舞う。
He always behaves like a gentleman.
緊張しても冷静に振舞うことが大切だ。
Even if you're nervous, it's important to act calmly.
2to treat someone to food or drink; to entertain or serve (guests).
今日は私が皆に寿司を振舞います。
I'll treat everyone to sushi today.
社長は新入社員に昼食を振る舞った。
The president treated the new employees to lunch.
お茶とお菓子を振舞って歓迎した。
They welcomed guests with tea and sweets.