Eyeball, optical globe looking everywhere initially (4)
I believe the answer is:
ogle
'eyeball' is the definition.
(I've seen this in another clue)
'optical globe looking everywhere initially' is the wordplay.
'initially' says to take the initial letters.
The initial letters of 'optical globe looking everywhere' is 'OGLE'.
(Other definitions for ogle that I've seen before include "Cast amorous glances" , "Amorous stare" , "Gawp" , "Stare lewdly" , "Close scrutiny" .)