肝
HSK 6liver
Explanation
(slang) to put in long hours, typically late into the night, playing (a video game); (of a video game) involving a lot of repetition in order to progress; grindy
Examples
他肝了一整晚玩电子游戏。
He worked hard all night playing video games.
这款游戏肝起来很磨人。
This game requires a lot of hard work to progress.