Abomination observed by me, reportedly (7)
I believe the answer is:
eyesore
'abomination' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
'observed by me reportedly' is the wordplay.
'observed' becomes 'sore' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'by' says to put letters next to each other.
'me' becomes 'I'.
'reportedly' indicates a 'sounds like' (homophone) clue.
'i' is a homophone of 'eye'.
'sore' put after 'eye' is 'EYESORE'.
Can you help me to learn more?
(Other definitions for eyesore that I've seen before include "Ugly object, hard on the sight" , "Hideous building" , "Blemish" , "Ugly sight, not nice to see" , "Blight" .)