In most dialects, primarily refers to the bellybutton or navel. Pronunciation may vary.
In Mesa Grande, millyepuu is "umbilical cord" while milyepuu (the "small" version of the former) is "navel/belly button". Other dialects may use pehaa "guts, intestines" to refer to the umbilical cord.
To Cuevas, millyepuu means both "belly button" and "umbilical cord".
May also be used to mean "spark plug" of a car.