look up any word, like eiffel tower:
 
1.
To avoid fulfilling a responsibility. To renege on an agreement.

The term comes from the word "cop," to steal. It is in general usage, and has been long before any "song" by Eminem.
I was going to go to the movies with Gillian last night, but she copped out on me and made her father dinner.
by Justin March 01, 2005
 
2.
quit, leavein the game. From 50 cent Feat. Eminem in Patiantly waiting
I copped out does that make me a quitta?
by Bridget September 16, 2003