Unwanted, half-hearted, pitiable Edward’s upset (2,4)
I believe the answer is:
de trop
'unwanted' is the definition.
(similar in meaning)
'half-hearted pitiable edward's upset' is the wordplay.
'half-hearted pitiable edward' becomes 'ported' (I can't explain this - if you can you should give a lot more credence to this answer).
'upset' says the letters should be written backwards.
'ported' in reverse letter order is 'DE TROP'.
Can you help me to learn more?
(Other definitions for de trop that I've seen before include "Not wanted, in the way - in France (2.4)" , "not to drink too much" , "Not wanted, in the way - from French" , "surplus to requirements" , "Deport from France, being in the way?" .)