Come round with a spare part to match (7)
I believe the answer is:
compare
'match' is the definition.
(thesaurus)
'come round with a spare part' is the wordplay.
'round' means one lot of letters goes inside another.
'with' is an insertion indicator.
'spare part' becomes 'pr' (I can't justify this - if you can you should give a lot more credence to this answer).
'a' placed into 'pr' is 'par'.
'come' going around 'par' is 'COMPARE'.
'to' is the link.
Can you help me to learn more?
(Other definitions for compare that I've seen before include "what discriminators do" , "Represent as similar; sounds like emcee" , "Look at differences and similarities between (things)" , "Contrast - liken" .)