mean business
To be very serious about completing a task or doing something, ardent; serious, not jokingly
I see you mean business.
I could tell my teacher meant business when she said that she would fail me unless I completed my homework.
I could tell my teacher meant business when she said that she would fail me unless I completed my homework.
Mean business
To be completely serious about something.
Alice: Here comes Charlie. Wait, what is he doing with that chainsaw?
Bob: Uh oh. I hope he doesn't mean business.
Bob: Uh oh. I hope he doesn't mean business.