Sentence examples for a big fish from inspiring English sources

"a big fish" is a correct and usable phrase in written English.
It can be used to refer to a literal large fish or as a metaphor for a person with influence or importance in a particular situation. Example: "The fisherman was ecstatic when he finally caught a big fish after hours of waiting." Example: "The new CEO of the company was seen as a big fish in the business world and was highly respected by his colleagues."