Nile reptiles (4)
I believe the answer is:
asps
'nile reptiles' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for asps that I've seen before include "people" , "Deadly snakes" , "Pass (anag)" , "Poisonous snakes" , "Cleopatra's cobras" .)