From Longman Dictionary of Contemporary Englishday returnˌday reˈturn noun [countable] British English TTCTTTa train or bus ticket that lets you go somewhere at a cheaper price than usual, if you go there and back on the same day
Examples from the Corpus
day return• She left early, bought a day return, and sat back to enjoy the journey.• Young orangs living free in the forest all day return in the afternoon for their meal of bananas and milk.• Since February 22, passengers buying a cheap day return have been able to get a second ticket for £1.• Typical fares: day return from Kilburn to Blackfriars, £2.40. 