Fish in a Japanese garden (3)
I believe the answer is:
koi
'fish in a japanese garden' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for koi that I've seen before include "Sort of carp" , "Ornamental carp variety" , "Colourful ornamental carp" , "Large Japanese carp" , "Kind of decorative carp" .)