Average lady leaving out a head of department unkindly (6)
I believe the answer is:
meanly
'out a head of department unkindly' is the definition.
I can't judge whether this defines the answer.
'average lady' is the wordplay.
'average' becomes 'mean' (type of average).
'lady' becomes 'ly' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'mean'+'ly'='MEANLY'
'leaving' acts as a link.
Can you help me to learn more?
(Other definitions for meanly that I've seen before include "in a despicable way" , "Unkindly; poorly" , "Ungenerously" , "In a sordid way" , "In a despicable, ignoble manner" .)