get after

verb3

1. •
   To move into action in pursuit of something.

   • He's wasting time at university not getting after his degree.
   • If you want to win, you've got to get after it.
2. •
   To move into action in attempt to catch or defeat another.

   • The defensive line needs to get after the quarterback.
   • Do you think the girl's going to ask you out? Get after her!
3. •
   To attempt to convince another to move into action.

   • Parents get after their children to do homework for the best.