Definition & Meaning of "big cheese"

What is the origin of the idiom "big cheese" and when to use it?

The origin of the idiom "big cheese" is not definitively known, but there are a few theories about its possible origins. One theory suggests that it may have originated from the Hindi word "chiz" or "chizzi," meaning "thing" or "person." British colonizers in India may have adopted and modified this term, leading to the use of "cheese" as a slang term for an important person. Another theory points to the fact that cheese, particularly large wheels of cheese, used to be a valuable and prized commodity. In the past, the person who had possession of the "big cheese" was considered to be important or influential. It is used to refer to a person who holds a position of importance, power, or influence, describing someone who is in a leadership role or has significant authority within a particular organization, group, or field.