Definition of "big fish" []

• An important influential person (noun)

WordNet. Princeton University. 2010.

• "“For bringing in big fish like tunas and marlins and things,” he said."
• "Perhaps he thought we were novices, for he insisted on showing us all sorts of absurd things – trolling-hooks, he called them; gaff hooks for landing big fish and a spoon that was certainly no spoon and did not fool us for a minute, being only a few hooks and a red feather."
• "Another big fish with humpy sort of fins sticking up, and horror, in the green water a big red mouth wide open."