Tolerate channel (5)
I believe the answer is:
brook
This clue is a double definition.
'tolerate' is the first definition.
(I know that tolerate can be written as brook)
'channel' is the second definition.
(thesaurus)
(Other definitions for brook that I've seen before include "Allow" , "stomach" , "Small fresh-water stream" , "Bear - small stream" , "running water" .)