The phrasal verb “wait up” means to stay awake because you are expecting someone to arrive.
Some Excerpts:
From TV shows, movies and novels
Closer
Clive Owen(Larry) used the phrasal verb “wait up” while talking to Julia Roberts(Anna) in the movie “Closer” by Mike Nichols as shown below:
Your scraps..
24 A lot like Love Amanda Peet Amaury Nolasco Ashley Jones Ashton Kutcher Bold & the Beautiful Brooke Logan Cameron Diaz Carrie Bradshaw Chris Noth Closer Cosmo Kramer(Seinfeld) Cynthia Nixon Desperate Housewives Drew Tyler Bell Elaine Benes(Seinfeld) Eternal Sunshine of the Spotless Mind Eva Longoria Parker Felicity Huffman Fernando Sucre Gabriel Byrne George Costanza(Seinfeld) Hunter Tylo In Treatment Jack Bauer Jack Black Jack Wagner Jason Alexander Jerry Seinfeld Jim Carrey Jude Law Julia Louis Dreyfus Julia Roberts Kate Winslet Katherine Kelly Lang Kiefer Sutherland Kim Cattrall Kristin Davis Kyle Lowder Lesley-Anne Down Lost Marcia Cross Matthew Fox Melissa George Michael Scofield Nick Marone Prison Break Ridge Forrester Ronn Moss Sarah Jessica Parker Seinfeld Sex & the City Stephanie Forrester Susan Flannery Teri Hatcher The Holiday The Lake House Wentworth Miller keanu Reeves