IPA: /ˈraʊndˌtrɪp/
KK: /ˈraʊndˌtrɪp/
A journey that goes from one location to another and then returns to the starting point, often using the same path.
I booked a roundtrip ticket for my vacation to New York.
Roundtrip → It is formed from "round" (from Old English *rund*, meaning circular or spherical) and "trip" (from Old French *tripe*, meaning a journey or travel). The word "roundtrip" refers to a journey that goes to a destination and returns to the starting point, creating a circular route.
Think of a journey that goes in a "circle" ('round') and then comes back, which is what a roundtrip means.
No commonly confused words.