What does kewai mean in hawaiian?

"Kewai" is not a Hawaiian word. It's possible you're thinking of a similar-sounding word in another language, or perhaps a misspelling.

It's important to note that Hawaiian pronunciation is quite different from English, so even slight variations in spelling can lead to a completely different word.

If you can provide more context or information about where you heard this word, I might be able to help you figure out what you're looking for.