This is the 2132nd most frequent Japanese word.
往復
Round trip.
往復 here is used as a verb indicating the act of commuting or traveling back and forth.
毎日、電車を使って会社と自宅を往復しています。
Every day, I commute back and forth between my workplace and home using the train.
往復 in this sentence refers to a round trip fare for transportation.
このバスの往復運賃はいくらですか？
How much is the round trip fare for this bus?
往復 is used as an attribute to qualify the type of ticket—indicating it is a ticket for traveling to and from a destination.