mean business
idiomPart ofbusiness
mean business — idiom
1. to be very serious about doing something, in a way that other people can clearly
1.idiom
Definition
to be very serious about doing something, in a way that other people can clearly see.
Example
The new coach arrived with a whistle and a clipboard, and the players knew she meant business.
When Dr. Tanaka raised his voice, the whole class realised he meant business.