Possible Clues:

• Channel running along the eaves of a building
• Threaten to go out to speak after close of meeting
• Idiomatic setting for a dirty mind
• Channel close to going on air
• Trough carrying rainwater
• Bad place for a bowling ball or the mind
• Sluice
• Area that's far from a strike zone
• Channel crossing's end, say
• End of broadcasting, say, for channel