Feeling dejected, having received penny for cleaning (7)
I believe the answer is:
mopping
'for cleaning' is the definition.
(mopping is a kind of cleaning)
'feeling dejected having received penny' is the wordplay.
'feeling dejected' becomes 'moping' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'having received' means one lot of letters goes inside another.
'penny' becomes 'p' (short for pence).
'moping' placed around 'p' is 'MOPPING'.
Can you help me to learn more?
(Another definition for mopping that I've seen is " Cleaning up".)