Give a once-over (3,2)
I believe the answer is:
eye up
'give a once-over' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for eye up that I've seen before include "Look at (someone) appraisingly" , "Look at (someone) as a potential partner" , "Consider sexual attractiveness of (someone)" , "Ogle" , "Check out" .)