This verb specifies the object is cut into several pieces. "Che" in the root of a verb often means "multiple things".
Compare with aakatt (achekaatt), "cuts". Identical plural form.
One entry in the Mesa Grande dictionary lists achekatt as the plural of aakatt "cuts", but this appears to be an error. The main entry for aakatt has achekaatt as the plural, and the Barona dictionary lists the same.