Fishy replacement parts (5)
I believe the answer is:
sprat
'fishy replacement parts' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'replacement parts' is the wordplay.
'replacement' indicates anagramming the letters.
'parts' with letters rearranged gives 'SPRAT'.
Can you help me to learn more?
(Other definitions for sprat that I've seen before include "Tiny fish" , "Traps for small fish" , "Small herring, often smoked or canned" , "Young herring" , "Mackerel bait?" .)