Crazy bloke in charge (5)
I believe the answer is:
manic
'crazy' is the definition.
(thesaurus)
'bloke in charge' is the wordplay.
'bloke' becomes 'man' (I've seen this in other clues).
'in charge' becomes 'ic'.
'man'+'ic'='MANIC'
(Other definitions for manic that I've seen before include "Unnaturally excited" , "Wildly energetic" , "Hectic" , "Ludicrously busy" , "Of mental state veering from depression to excitement" .)