Admonish ring-leader for interrupting a head (8)
I believe the answer is:
reproach
'admonish' is the definition.
(thesaurus)
'ring-leader for interrupting a head' is the wordplay.
'leader' says to take the initial letters.
'for' becomes 'pro' (I've seen this before).
'interrupting' indicates putting letters inside.
'a head' becomes 'each' (I have seen 'A head' mean 'each' so perhaps 'head' could also mean 'each'**).
The first letter of 'ring' is 'r'.
'pro' placed within 'each' is 'eproach'.
'r'+'eproach'='REPROACH'
(Other definitions for reproach that I've seen before include "Rebuke or expression of disappointment" , "An expression of disapproval" , "Censure - or preach (anag)" , "criticise" , "Express disapproval, admonish" .)