What is the meaning of Fini_flight?

The final pilot-in-command, pilot-flying flight of a pilot during a stage of life, such as on a particular aircraft, aircraft type, airline, professional life, military life, career at a company, assignment in a unit, as an active duty pilot, etc. Typically a celebratory flight, with congratulatory accoutrements; it may be a regular duty flight, or an additional special flight.

Source: wiktionary.org