quit on (one)
1. To stop functioning, either properly at all, especially while one is in the middle of using it. I can't believe this crappy old computer quit on me when I was halfway through my term paper! I've been looking for a new lawnmower ever since our old one quit out on us last week.
2. To stop helping, supporting, or assisting one in some endeavor. A lot of my friends quit on me after I had my baby because they couldn't appreciate how much my priorities had changed. Sam is a bright kid, but he needs a lot of encouragement. If you quit on him, he'll quit caring too.
3. To give up; to stop putting in the required effort. No, no, you can't stop moving now, we're nearly at the camp. Don't you quit on me now!
4. To quit or resign from one's job, especially very suddenly or unexpectedly. Nearly a third of my team has quit on me over the last six months—at this rate, we won't have enough staff to finish even one of our projects by Christmas! I don't want to just quit on them, but every day I stay in that job feels like torture.
quit on someone
1. [for something] to quit while someone is using it. This stupid car quit on me. I hope this thing doesn't quit on me.
2. [for one] to leave one's job, usually suddenly or unannounced. Wally, the park supervisor, quit on us at the last minute. My assistant quit on me.
1. To stop helping or working with someone, especially when the support or assistance is needed: My friends quit on me when I really needed them.
2. To stop functioning properly for someone; give out on someone: The car's battery quit on us when we were a mile from the city. My knee quit on me in the last mile of the marathon.