godan verb (-su), transitive verb
Used for stopping an action or habit, often with a nuance of abandoning something one was doing. Common in casual speech; やめる is more general.
もう遅いから、今日は仕事をよそう。
It's already late, so let's call it a day and stop working.
タバコは体に悪いから、よしたほうがいいよ。
Smoking is bad for your health, so you should quit.