noun, noun or participle which takes 'suru'
round trip; going and returning
Literary or formal term for a round trip; in everyday language 往復 is far more common. Can be used as a noun or with する.
東京と大阪の間を一日で往返するのは大変だ。
It's tough to make a round trip between Tokyo and Osaka in one day.
往復 is the standard modern word for 'round trip' and is used in everyday conversation, tickets, and schedules. 往返 is a literary synonym rarely used outside formal or old-fashioned writing.
Compound of 往 (going) and 返 (returning). The reading おうへん is the on'yomi of both characters. The word is now largely replaced by 往復 in modern usage.