In Star Trek: The Motion Picture, what is the name of Admiral Kirk’s former starship?

In Star Trek: The Motion Picture, Admiral Kirk’s former starship is the USS Enterprise.

The vessel is the Constitution-class USS Enterprise, NCC-1701, commanded by Kirk during the original Star Trek television series and its later films. At the beginning of the movie, Kirk has become an admiral and works at Starfleet Command, while Captain Willard Decker oversees a major refit of the Enterprise.

Kirk takes operational command during the crisis involving the entity V’Ger. The Enterprise’s refit gives the familiar ship a redesigned appearance, including a larger engineering section, longer nacelles, and a new bridge interior. This version became one of the most recognizable film designs in the franchise.

The question refers to Kirk’s former command in the story, not to every starship he commands across the series. Kirk later commands other Enterprise versions, including the Enterprise-A in subsequent films.