Fish straying out (8)
I believe the answer is:
stingray
'fish' is the definition.
(type of fish)
'straying out' is the wordplay.
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'straying' is an anagram of 'STINGRAY'.
(Other definitions for stingray that I've seen before include "TV show" , "Flatfish with barbed spine" , "Fish with venomous tail" , "swimmer" , "menace in the water" .)