Primarily omniscient, wise learned bird (3)
I believe the answer is:
owl
'bird' is the definition.
(I know that owl is a type of Bird of prey)
'primarily omniscient wise learned' is the wordplay.
'primarily' says to take the initial letters.
The first letters of 'omniscient wise learned' is 'OWL'.
(Other definitions for owl that I've seen before include "Wise person" , "Mainly nocturnal bird" , "Wise old night-flier" , "Harry Potter's Hedwig, for instance" , "Night hunter" .)