Two
It is most commonly two words.
coxal
The word you are looking for is pelvis.
Another name for the Hipbone is the Pelvis
The proper name for the hipbone is the coxal bone or os coxae.
Pelvis.
hipster
Pelvis.
Iliac is the medical term meaning area around the hipbone.
At the hip/pelvis
It is used as one word.
liver