Suff is a word perculiar to the West Midlands meaning the drain.
Shakespeare used it in Troilius and Cressida Act 5 Scene 1 when one servant insults the master of another servant. Except that in most copies of the play it now says south instead of suff because some printer made a typo which makes nonsense of the passage:
Why, his masculine whore. Now, the rotten diseases
of the south, the guts-griping, ruptures, catarrhs,
loads o' gravel i' the back, lethargies, cold
palsies, raw eyes, dirt-rotten livers, wheezing
lungs, bladders full of imposthume, sciaticas,
limekilns i' the palm, incurable bone-ache, and the
rivelled fee-simple of the tetter, take and take
again such preposterous discoveries!