Hawaiian Nut
Macadamia?
I don't have any idea how "slide," or "steel" guitars became part of the Hawaiian music scene.
Historically, the standard steel or nylon string guitar is known as a "Spanish guitar" to distinguish it from the "Hawaiian guitar" which is not fretted, but played with a slide.
To keep the strings high enough so the steel bar doesn't bump into the frets, Hawaiian guitars have Hawaiian nuts:
This instrument was made with the tall Hawaiian nut as standard equipment.
You can also purchase add-on Hawaiian nut extenders to raise the strings on a standard guitar, so you can play both ways. . .
Before:
After:
Easy, wasn't it?