noun
Colloquial term for someone who is obsessed with work, often to the detriment of other aspects of life. Can be used self-deprecatingly or critically.
彼は完全に仕事バカで、休日もずっと働いている。
He's a total workaholic; he works even on his days off.
仕事バカにならないように、趣味の時間も大切にしている。
I make sure to value my hobby time so I don't become a workaholic.
Compound of 仕事 (work) and バカ (fool). The exact origin is uncertain, but it likely emerged as a colloquial expression to describe someone foolishly devoted to work.