单程票(dān chéng piào) - single ticket, one-way ticket in Mandarin

单程票 (dānchéngpiào) is a single, one-way ticket. 单 (dān) means single or one, 程 (chéng) here means "journey, leg of a trip", and 票 (piào) is ticket, so together it names a ticket for one leg of a journey only, with no return covered.

It is the natural opposite of 往返票 (wǎngfǎnpiào, return ticket), and the two words are usually taught and used together, at train stations, airports and bus counters alike.

程 (chéng) on its own rarely stands as a word; it mostly shows up bolted onto other characters like this, in words such as 行程 (xíngchéng, itinerary) and 过程 (guòchéng, process). Recognising it as "journey/course" helps 单程 (dānchéng, one-way) and 往返 (wǎngfǎn, return) make more sense as a pair.