Watches; notices (8)
I believe the answer is:
observes
I believe this is a double definition.
'watches' is the first definition.
('observe' can be a synonym of 'watch')
'notices' is the second definition.
('observe' can be a synonym of 'notice')
(Other definitions for observes that I've seen before include "Notices; comments" , "Acts as member of royal corps" , "Notices or becomes conscious of" , "notes" .)