codeshare

/K OW1 D SH EH0 R/
noun
  1. 1

    Agreement whereby an airline buys space on another airline and markets the extra space as its own. Often used to increase a route network without the costs of running a full service.

verb
  1. 1

    To buy space on (a flight) in this way.

Source: https://en.wiktionary.org/wiki/codeshare