Royal survivor of short rebuff (4)
I believe the answer is:
parr
'royal survivor' is the definition.
The definition and answer can be both animals as well as being singular nouns.
Maybe there's an association between them I don't understand?
'of short rebuff' is the wordplay.
'of' becomes 'par' (I can't justify this - if you can you should give a lot more credence to this answer).
'short' suggests taking the first letters.
The initial letter of 'rebuff' is 'r'.
'par'+'r'='PARR'
Can you help me to learn more?
(Other definitions for parr that I've seen before include "Young salmon; Queen Catherine ---" , "Henry's sixth (his third 7!)" , "Wife surviving" , "old trout?" , "Young salmon or trout" .)