How do you say hard head in hawaiian?

There isn't a direct translation for "hard head" in Hawaiian that conveys the same meaning as the English idiom. However, you could use phrases like:

* Poʻo paʻakikī (literally "hard head") - This translates literally but might not convey the stubborn or inflexible connotation of "hard head."

* Poʻo ʻāʻī (literally "stiff neck") - This implies stubbornness and resistance to change.

* Poʻo ʻēheu (literally "head of a fish") - This is a figurative expression, meaning "thick-headed" or "slow to understand."

* Poʻo ikaika (literally "strong head") - This implies a strong-willed or determined personality, which could be seen as positive or negative depending on the context.

The best translation would depend on the specific context and the intended meaning.