Here's a breakdown:
* Mahalo: This is the standard Hawaiian word for "thank you."
* Piha: This could refer to a few things:
* Pihana: Meaning "to be filled" or "full."
* Piha (place): A beach on the west coast of Oahu.
* Piha (sound): A type of sound or noise.
Without more context, it's impossible to determine the intended meaning of "mahalo piha."
If you can provide more context or the full sentence where you encountered this phrase, I might be able to help you understand its meaning.