To quit one's job; to resign or leave a position of employment.
来月、会社の仕事を辞めることにした。
I've decided to quit my job at the company next month.
彼は体調不良を理由に仕事を辞めた。
He quit his job for health reasons.
仕事を辞める前に、次の仕事を探したほうがいい。
It's better to look for the next job before quitting your current one.