be all business

1. To be very serious and focused primarily or solely on the pursuit, endeavor, or matter at hand; to be no-nonsense. He's actually a pretty funny, laid-back guy when he's out of the office, but he's all business during working hours. Everyone was laughing and joking before the meeting started, but the moment the clock struck nine, it was all business in there. The boss is always all business. I don't think I've ever seen him smile before!

2. Of a machine or piece of technology, to be designed purely to achieve, enable, or enhance optimal performance. While there are lots of frilly luxury touches around the interior of the car, the dashboard is all business—sleek and refined, for a pure automotive experience. My brother's gaming PC is impressively powerful, but it's covered in weird blinking lights and designed like it's trying way too hard to look cool. I would much rather have a computer that's all business. I just need a phone that's all business—this stupid one drops calls all the time.

3. Done purely out of business interests, as opposed to any personal motivations. I know you're upset with me for taking the job at the other company, but I never did it out of spite or malice. It was all business. This is all business, Sal. If you're going to take these sorts of things personally, then maybe this is not the industry for you. I truly do hate having to lay off any of my employees, and I try to emphasize to them that it's all business.