Well-oiled instrument cut, then cut again (8)
I believe the answer is:
banjaxed
'cut again' is the definition.
The answer and definition are different parts of speech. However, past participle verbs and adjectives occasionally mean the same thing.
'well-oiled instrument cut' is the wordplay.
I cannot quite see how this works, but
'instrument' could be 'ban' (ban is a kind of instrument) and 'ban' is found in the answer.
'cut' could be 'axed' (I've seen this before) and 'axed' is located in the answer.
A single letter 'j' remains which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
'then' acts as a link.
Can you help me to learn more?
(Other definitions for banjaxed that I've seen before include "Ruined (slang)" , "Spoiled" .)