A task so prolonged or difficult, it seems as though you're taking on more than you bargained for. Once completed, you feel so irritated (or relieved, depending on the situation) that you can't help but talk about it to someone.
Sophie: I didn't get picked up yesterday afternoon and had to walk home. It took me two bloody hours!
John Smith: That must've been a mission and a half.
John Smith: That must've been a mission and a half.
by MysteryGirl05 November 19, 2013
Get the Mission and a halfmug.