Legendary character quick to get out of uniform (5)
I believe the answer is:
faust
'of uniform' is the definition.
The definition suggests a singular noun which matches the answer.
'legendary character quick to get' is the wordplay.
'legendary character' becomes 'u' (I am not sure about the 'legendary' bit.).
'quick' becomes 'fast' (similar in meaning).
'to get' is an insertion indicator.
'u' put inside 'fast' is 'FAUST'.
'out' acts as a link.
Can you help me to learn more?
(Other definitions for faust that I've seen before include "Alchemist" , "Opera" , "Cautionary tale" , "Goethe's damned soul" , "1 28 [EPIC POEM]" .)