Noun. When you're on a really hard part in a video game and you keep trying and trying, but you keep on losing. Gets you very frustrated and makes you want to throw the controller through the TV. A common gamer's grind goes as follows:

1) Discovery of level/task
2) Several attempts and failures of task
3) Frustration
4) Attempts to do task through frustration
5) More frustration

This can end in two ways:

6) Random luck
7) Victory

or:

6) Take a break and come back later
7) Victory