One refusing to change out of uniform into elaborate stitched mink (5-2-3-3)
I believe the answer is:
stick-in-the-mud
'one refusing to change out' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'uniform into elaborate stitched mink' is the wordplay.
'uniform' becomes 'U' (phonetic alphabet: alpha, bravo, charlie etc.).
'into' indicates putting letters inside.
'elaborate' indicates an anagram (an elaborate version of the letters).
'stitched'+'mink'='stitchedmink'
'stitchedmink' with letters rearranged gives 'stickinthemd'.
'u' put into 'stickinthemd' is 'STICK-IN-THE-MUD'.
'of' is the link.
Can you help me to learn more?
(Other definitions for stick-in-the-mud that I've seen before include "Old fashioned" , "One who resists change" , "Resister of change" , "A reactionary" , "Staid or predictable conservative person" .)