Look for an equal (4)
I believe the answer is:
peer
I believe this is a double definition.
'look' is the first definition.
(peering is a kind of looking)
'an equal' is the second definition.
('peer' can be a synonym of 'equal')
'for' is the link.
(Other definitions for peer that I've seen before include "count, perhaps" , "Noble; look intently" , "Look dimly at lord" , "role in Iolanthe" , "Squint" .)