Keenly observe what's in orbit (7)

I believe the answer is:

eyeball

I believe this clue is a double definition.

'keenly observe' is the first definition.
(eyeball can mean to stare at)

'what's in orbit' is the second definition.
(orbit can mean an eye socket)

(Other definitions for eyeball that I've seen before include "It was cut in Un Chien Andalou" , "Ocular orb" , "Watch" , "Closely examine" , "One faces one in confrontation" .)

I've seen this clue in The Times.

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