Bird sacred to ancient Egyptians (4)
I believe the answer is:
ibis
'bird sacred to ancient egyptians' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ibis that I've seen before include "Bird, sacred to ancient Egyptians" , "Large wading birds with down-curved bills" , "Near-colourless mineral" , "Wader worshipped by ancient Egyptians" , "Slowly discharge" .)