Attendants keeping idiot in corridors (8)
I believe the answer is:
passages
'corridors' is the definition.
(I've seen this before)
'attendants keeping idiot' is the wordplay.
'attendants' becomes 'pages' (page is a kind of attendant).
'keeping' means one lot of letters goes inside another (some letters kept inside).
'idiot' becomes 'ass' (both can mean a stupid person).
'pages' enclosing 'ass' is 'PASSAGES'.
'in' is the link.
(Other definitions for passages that I've seen before include "Sections of a text" , "Narrow streets or routes" , "Corridors, ways through" , "sections of the speech" , "Texts" .)