"Tube carrying rainwater"

This is a reversal clue - look for indicators like 'back', 'returned', 'up' (in down clues), or 'west' (in across clues)

Break down the clue into definition and wordplay parts

Answer: DOWNPIPE | Definition: 'Tube carrying rainwater' | Wordplay: PIPE DOWN=a way to tell someone to “shut up”, with the order “inverted”