Servant traps donkey in corridor (7)
I believe the answer is:
passage
'corridor' is the definition.
(I know that corridor can be written as passage)
'servant traps donkey' is the wordplay.
'servant' becomes 'page' (I've seen this before).
'traps' indicates putting letters inside.
'donkey' becomes 'ass' (ass is a term for a donkey).
'page' placed around 'ass' is 'PASSAGE'.
'in' is the link.
(Other definitions for passage that I've seen before include "Way through something" , "Aisle" , "Transit - part of book etc" , "street" , "Short section of text" .)