Stray bird seen around noon (6)
I believe the answer is:
wander
'stray' is the definition.
('wander' can be a synonym of 'stray')
'bird seen around noon' is the wordplay.
'bird' becomes 'wader' (wader is a kind of bird).
'seen around' means one lot of letters goes inside another.
'noon' becomes 'n' (**).
'wader' placed around 'n' is 'WANDER'.
(Other definitions for wander that I've seen before include "Go to and fro" , "Meander" , "Move about aimlessly" , "endless travel" , "Stray" .)