Of the upper hipbone (5)
I believe the answer is:
iliac
'of the upper hipbone' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for iliac that I've seen before include "Pertaining to hip bone" , "bottom of a hip bone" , "Like certain body parts" , "Relating to part of the hip bone" , "hipbone" .)