big cheese

An important, successful, or influential person. Jacob thinks he's a big cheese now that he's been promoted to assistant manager. I'm the big cheese around here, so you have to do what I say.

Also, big shot or gun or wheel or enchilada . An important, powerful person; the boss. For example, She loved being the big cheese of her company; the big guns in Congress are bound to change the President's bill; you'd better not act like a big shot among your old friends; Harry was the big wheel in his class ; and You'll have to get permission from the big enchilada. The first term dates from the late 1800s and its origin is disputed. Some think it comes from the Urdu word chiz or cheez for "thing," but others hold it plays on the English word "chief." Big gun is much older, dating from the early 1800s; big shot became very popular in the late 1920s, particularly when used for underworld leaders of gangsters; big wheel dates from about the same period. Big enchilada, often put as the big enchilada, is the newest, dating from the early 1970s.

A very important person. The phrase seems to have come from, literally, a very large wheel of cheese. After President Jefferson was given one of Cheshire in 1802, other dairies made and displayed huge wheels for publicity purposes. The cheeses attracted lots of attention, and so it wasn't much of a jump to referring to someone who attracted attention as a “big cheese.” Although some have suggested that “cheese” came from the Hindu word “chiz,” for “thing” that the British heard as “cheese,” no paper trail exists to show that Americans started using the phrase though any transatlantic connection. Similar “big” phrases are more common, such as big deal and big wheel.