Channel for Midnight Express? (6)
I believe the answer is:
gutter
'channel' is the definition.
(I know that gutter is a type of channel)
'midnight express?' is the wordplay.
'midnight' becomes 'g' (the middle letter in 'night').
'express?' becomes 'utter' (synonyms).
'g'+'utter'='GUTTER'
'for' acts as a link.
(Other definitions for gutter that I've seen before include "piping?" , "Street channel for carrying off rainwater" , "Someone removing contents" , "Rain channel; (flame) start to die" , "dirty channel?" .)