Gaze fixedly (5)
I believe the answer is:
stare
'gaze fixedly' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for stare that I've seen before include "Long fixed look" , "Rates (anag.)" , "Gawp" , "'Look fixedly, without blinking (5)'" , "Look hard" .)