Anger that king has broken a bone (7)
I believe the answer is:
stirrup
'a bone' is the definition.
(bone of the ear)
'anger that king has broken' is the wordplay.
'anger' becomes 'stir up' (to stir up is to anger or provoke).
'that king' becomes 'R' (abbreviation for rex, king in Latin).
'has broken' means one lot of letters goes inside another (inserted letters break in).
'stirup' going around 'r' is 'STIRRUP'.
(Other definitions for stirrup that I've seen before include "Rider's foot loop" , "Bit of tack" , "rider needs" , "Equestrian foot support" , "supporter?" .)