Unacceptable fruit given to head of department, old-fashioned (8)
I believe the answer is:
outdated
'old-fashioned' is the definition.
(I've seen this before)
'unacceptable fruit given to head of department' is the wordplay.
'unacceptable' becomes 'out' (out can mean incorrect or inappropriate).
'fruit' becomes 'date' (date is a kind of fruit).
'given to' is a charade indicator (letters next to each other).
'head of' says to take the initial letters.
The first letter of 'department' is 'd'.
'out'+'date'+'d'='OUTDATED'
(Other definitions for outdated that I've seen before include "No longer valid or fashionable" , "Passe" , "Obsolete, antiquated" , "old hat" , "Pass" .)