Spend a very long time in the corridor (7)
I believe the answer is:
passage
'the corridor' is the definition.
(I've seen this before)
'spend a very long time' is the wordplay.
'spend' becomes 'pass' (synonyms).
'a very long time' becomes 'age' (I've seen this before).
'pass'+'age'='PASSAGE'
'in' acts as a link.
(Other definitions for passage that I've seen before include "course" , "Corridor or narrow laneway" , "crossing" , "Literary extract" , "Transit - part of book etc" .)