Ilium (7)
(Other definitions for hipbone that I've seen before include "bit of leg" , "Large part of skeleton" , "One half of the pelvis" .)
'ilium' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for troy that I've seen before include "System of weights for measuring precious metals and gemstones" , "City destroyed" , "City besieged by Greeks to rescue Helen" , "part of Asia Minor" , "Ancient city in Asia Minor" .)