Keep watch (7)
I believe the answer is:
observe
I believe this is a double definition.
'keep' is the first definition.
(I know that keep can be written as observe)
'watch' is the second definition.
(I know that watch can be written as observe)
(Other definitions for observe that I've seen before include "See - say" , "Spot, watch" , "obey" , "What this newspaper does?" , "Look at" .)