Idle head given gin cocktail (7)
I believe the answer is:
loafing
'idle' is the definition.
(I've seen this in another clue)
'head given gin cocktail' is the wordplay.
'head' becomes 'loaf' (slang term for the head).
'given' says to put letters next to each other.
'cocktail' indicates an anagram.
'gin' anagrammed gives 'ing'.
'loaf'+'ing'='LOAFING'
(Other definitions for loafing that I've seen before include "not working" , "Lazing about" , "Being idle" , "Idling, hanging around" .)