Repairs past being done when one is lacking ___ ? (5,5)
I believe the answer is:
spare parts
'repairs' is the definition.
Although both the answer and definition are plural nouns, I don't see how they can define each other.
'past being done when one is lacking ?' is the wordplay.
I cannot quite understand how this works, but
'being' could be 'rep' (rep is a kind of being) and 'rep' is located in the answer.
'one' could be 'a' (a thing is one thing) and 'a' is located in the answer.
The remaining letters 'sparts' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
(Other definitions for spare parts that I've seen before include "accessories" , "Don't be merciless on everything" , "offered for replacements" , "Replacement components" , "Pare straps (anag.)" .)