Maybe watch circling bird initially in wood (6)
I believe the answer is:
timber
'wood' is the definition.
(I've seen this before)
'maybe watch circling bird initially' is the wordplay.
'maybe watch' becomes 'timer' (a watch might be used to time something).
'circling' is an insertion indicator (circling can mean going around or containing).
'initially' indicates taking the first letters.
The initial letter of 'bird' is 'b'.
'timer' going around 'b' is 'TIMBER'.
'in' acts as a link.
(Other definitions for timber that I've seen before include "Lumberjack's warning call" , "The tree's falling!" , "wooden" , "board" , "Wood prepared for use in carpentry or building" .)