Verb (5-dan, う, intransitive)
1. to behave; to conduct oneself; to act
だからどう振る舞っていいか分からなかった。That's why I didn't know how to behave.
Verb (5-dan, う, transitive)
2. to treat (someone) to (food or drink); to entertain (e.g. to lunch)
もしよければ、わしにもコーヒーを振る舞ってはもらえぬかな。If you don't mind, could you treat me to some coffee as well?