Ought a Head of State to jostle? (8)
I believe the answer is:
shoulder
'jostle?' is the definition.
(thesaurus)
'ought a head of state' is the wordplay.
'ought' becomes 'should' ('should' can be a synonym of 'ought').
'a head of state' becomes 'er' (abbreviation for Elizabeth Regina).
'should'+'er'='SHOULDER'
'to' is the link.
(Other definitions for shoulder that I've seen before include "Carry a burden" , "Cut of meat" , "Between the neck and the upper arm (8)" , "cut of beef" , "take responsibility?" .)