1. rude slang To travel or depart from some place very quickly or hurriedly. A possessive pronoun can be used between "shag" and "ass." We'd better shag ass if we're going to get to the airport on time! When we saw the silhouette of a creepy old woman at the top of the stairs, we shagged ass out of that spooky old as fast as we could.

2. rude slang To leave or get out of something or some place very lazily or reluctantly. A possessive pronoun can be used between "shag" and "ass." There's not much that would make me shag my ass out of bed at five in the morning.