Search briefly for toilet (3)
I believe the answer is:
loo
'toilet' is the definition.
(loo is a kind of toilet)
'search briefly' is the wordplay.
'search' becomes 'look' ('look' can be a synonym of 'search').
'briefly' means to remove the last letter.
'look' with its final letter removed is 'LOO'.
'for' is the link.
(Other definitions for loo that I've seen before include "In which one goes" , "Little boys' room" , "Ladies, perhaps" , "Rest room" , "Lavatory - old card game" .)