Watch drinking: wine knocked back's not easy to deal with (7)
I believe the answer is:
stroppy
'knocked back's not easy to deal with' is the definition.
I can't tell whether this defines the answer.
'watch drinking wine' is the wordplay.
'watch' becomes 'spy' (I've seen this in another clue).
'drinking' means one lot of letters goes inside another (inserted letters are consumed or drunk).
'wine' becomes 'trop' (I can't justify this - if you can you should give a lot more credence to this answer).
'spy' placed around 'trop' is 'STROPPY'.
Can you help me to learn more?
(Other definitions for stroppy that I've seen before include "Awkward to handle" , "like a razor-sharpener?" , "Difficult" , "Bad-tempered, argumentative" , "Unhelpful" .)