Turn up to support retiring fur supplier (5)
I believe the answer is:
coypu
'fur supplier' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'turn up to support retiring' is the wordplay.
'turn' says the letters should be written in reverse.
'to support' says to put letters next to each other (in a down clue, some letters hold others up).
'retiring' becomes 'coy' (I've seen this in other clues).
'up' written backwards gives 'pu'.
'pu' put after 'coy' is 'COYPU'.
Can you help me to learn more?
(Other definitions for coypu that I've seen before include "Beaver lookalike" , "aquatic mammal" , "Large South American aquatic rodent" , "Aquatic beaver-like rodent" , "Large South American beaver-like rodent" .)