Noun
Verb (する, intransitive)
1. making a round trip; going and returning; coming and going
何往復したか覚えてない。I don't remember how many round trips I made.
2. round-trip ticket; return ticket
往復を買ったほうが安いよ。It's cheaper to buy a round-trip ticket.
Noun
Verb (する, intransitive)
3. correspondence; exchanging (of letters)
メールは何回も往復したけど、会ったのは、あの会議だけだ。We exchanged emails many times, but the only time we met was at that meeting.
4. keeping company (with); socializing; visiting each other