For something that is captivating or intriguing:
* Nani: This word means "beautiful" but can also be used to express something that is captivating or fascinating.
* Kupanaha: This word means "wonderful" or "amazing" and can be used to describe something that is fascinating.
* Hoʻohiwahiwa: This word means "to be remarkable" or "to be awe-inspiring" and can be used to describe something that is fascinating in its beauty or complexity.
For something that is intellectually stimulating or interesting:
* Nānā: This word means "to observe" or "to pay attention to" and can be used to describe something that is intellectually stimulating or interesting.
* Hoʻomaopopo: This word means "to understand" or "to comprehend" and can be used to describe something that is fascinating in its complexity or depth.
Ultimately, the best way to say "fascinating" in Hawaiian depends on the specific context and nuance you want to convey.