Jules Verne captain
I believe the answer is:
'jules verne captain' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for nemo that I've seen before include "Fish sought in film" , "- me impune lacessit (motto of Scotland)" , "commander for the Nautilus" , "Captain of the Nautilus" , "Jules Verne's submarine captain" .)