Gator cousin (4)
I believe the answer is:
croc
'gator cousin' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for croc that I've seen before include "Large, bony-plated reptile (abbr)" , "Small animal" , "Single-handed mariner's nemesis" , "Snapper" , "Reptile (abbrev.)" .)