When the dog bounds round in, retreats (7)
I believe the answer is:
spaniel
'when the dog' is the definition.
I can't tell whether this definition defines the answer.
'bounds round in retreats' is the wordplay.
'bounds' becomes 'leaps' ('leap' can be a synonym of 'bound'**).
'round' means one lot of letters goes inside another.
'retreats' says the letters should be written in reverse (I've seen 'retreat' mean this).
'leaps' going around 'in' is 'leinaps'.
'leinaps' reversed gives 'SPANIEL'.
Can you help me to learn more?
(Other definitions for spaniel that I've seen before include "See 13" , "Droopy-ear dog" , "Type of dog" , "[HOUND]" , "Kind of dog, may be a cocker" .)