Bird initially over western lake (3)
I believe the answer is:
owl
'bird' is the definition.
(I know that owl is a type of bird of prey)
'initially over western lake' is the wordplay.
'initially' indicates taking the first letters.
The initial letters of 'over western lake' is 'OWL'.
(Other definitions for owl that I've seen before include "One swoops" , "One flying" , "Wise old bird" , "Lear's loved a Pussy-cat" , "Creature" .)