Pixar swimmer (4)
I believe the answer is:
nemo
'pixar swimmer' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for nemo that I've seen before include "- me impune lacessit (motto of Scotland)" , "commander for the Nautilus" , "Jules Verne captain" , "Finding -, animated film" , "Fish sought in film" .)