Sting-ray possibly getting sidetracked (8)
I believe the answer is:
straying
'getting sidetracked' is the definition.
(I've seen this before)
'sting-ray possibly' is the wordplay.
'possibly' indicates anagramming the letters.
'sting'+'ray'='stingray'
'stingray' anagrammed gives 'STRAYING'.
(Other definitions for straying that I've seen before include "Errant" , "aberration" , "Being bad" , "Drifters may be" , "Getting sidetracked" .)