Lunatic charged head of Government in fact (8)
I believe the answer is:
deranged
'lunatic' is the definition.
(thesaurus)
'charged head of government in fact' is the wordplay.
'charged' becomes 'ran'.
'head of' indicates taking the first letters.
'in' indicates putting letters inside.
'fact' becomes 'deed'.
The first letter of 'government' is 'g'.
'ran'+'g'='rang'
'rang' inserted into 'deed' is 'DERANGED'.
(Other definitions for deranged that I've seen before include "Crackpot" , "bananas" , "Mentally unbalanced" , "totally without reason" , "Lunatic" .)