The power of a government executive, usually a governor, to veto some parts of a bill passed by the legislature while signing other portions into law.
Executive power to reject a section of a bill, esp. one containing specific appropriations, without vetoing the entire bill.
I'm sorry the speaker isn't here, he's up on the hill on last-minute negotiations. He's going over his prenup and wants a line-item veto. (The West Wing, Season 2, Episode 18, Josh)