Wild, hit out regularly? Silly (5)
I believe the answer is:
idiot
'silly' is the definition.
(thesaurus)
'wild hit out regularly?' is the wordplay.
'regularly?' indicates alternate letters (regularly take one letter, leave next etc.).
'wild'+'hit'+'out'='wildhitout'
The alternate letters of 'wildhitout' are 'IDIOT'.
(Other definitions for idiot that I've seen before include "Foolish person" , "Blockhead" , "Stupid person" , "Ignoramus's" , "Simpleton" .)