Difficult militarist losing head with charge (7)
I believe the answer is:
awkward
'difficult' is the definition.
(I've seen this before)
'militarist losing head with charge' is the wordplay.
'militarist' becomes 'hawk' (hawk is a kind of militarist).
'losing head' means to remove the first letter.
'with' means one lot of letters go next to another.
'charge' becomes 'ward' (I've seen this before**).
'hawk' with its first letter taken off is 'awk'.
'awk'+'ward'='AWKWARD'
(Other definitions for awkward that I've seen before include "Not graceful" , "Clumsy and ungainly" , "Causing difficulty" , "Uncooperative" , "Clumsy or maladroit" .)