Once-over (4)
I believe the answer is:
scan
'once-over' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for scan that I've seen before include "Scrutinise; glance over" , "Examine (to transmit)" , "Examine closely to analyse metrically" , "Survey - check-up" , "Survey - fit in metrically" .)