Grant, say, protecting an island songbird (6)
I believe the answer is:
canary
'island songbird' is the definition.
(bird found on the Canary Islands)
'grant say protecting an' is the wordplay.
'grant say' becomes 'cary' (actor Cary Grant).
'protecting' indicates putting letters inside.
'cary' placed around 'an' is 'CANARY'.
(Other definitions for canary that I've seen before include "Kind of yellow" , "Yellow singing bird" , "Bright yellow bird" , "Pet bird" , "Caged song bird" .)