big kahuna

[ big kuh-hoo-nuh ]
/ ˈbɪg kəˈhu nə /

noun Slang.

the most important or dominant person or thing: He’s the big kahuna of a large travel agency.Their scholarship program is the industry’s big kahuna.

Origin of big kahuna

First recorded in 1955–60; see origin at big1, kahuna
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019