Guff is either rubbish chat or a proper stink, depending on what’s offending you more. If someone’s talking guff, they’re waffling nonsense, chatting absolute bollocks, or padding things out with pointless fluff. If something smells like guff, it’s rank. Honestly, it’s a top-tier word for everyday disappointment.
"Mate, that meeting was pure guff, forty slides and not one actual point. Then Dave let one off and the room went full hotbox. Only useful bit was the biscuits."