Live It Up Meaning

(idiomatic) To enjoy oneself, to have fun.

Example: 1999, Donald Richie - The Films of Akira Kurosawa page 174
  It is very like the philosophy that opens and closes Yojimbo—that a long life living on gruel in the country is better than short life of living it up in city.
1989, Aerosmith - Love in an Elevator
  Love in an elevator. Livin' it up when I'm going down!
1978, TIME - Letters
  Just as any grandmother or grandfather will tell you that their best days were spent during the Depression, anyone who was 18 and living it up in 1968 will tell you they spent their better days at this time.