noun

• (informal, uncountable) Nonsensical talk or thinking.
  "“… That woman is stark mad, Lord Stranleigh.[…]If she had her way, she’d ruin the company inside a year with her hare-brained schemes ; love of the people, and that sort of guff.”"
• (informal, uncountable) Superfluous information.
• (informal, uncountable) Insolent or otherwise unacceptable remarks.
  "“Oh, my God. Did-did you guys kill him?” “No! No one murdered him” “No! What... He was just...” “We found him in there.” “(laughs) I'm just giving you guff. And, uh, just so you know, I am feeding on you guys right now.”"
• (slang, countable) A fart; act of breaking wind.

verb

• (slang) To fart.
• (slang) To mislead.
  ""Let me see if I get you. You can't bear to help convict Ashe of murder because you doubt if he's guilty, so you're scooting. Right?" […]"That's close enough," Wolfe said. "Not close enough for me. If you expect me to[…] invite a stiff fine for running out on a subpoena[…], don't try to guff me. Say we doubt if Ashe is guilty, but we think he may get tagged because we know Mandelbaum wouldn't go to trial without a good case. Say also our bank account needs a shot in the arm, which is true. So we decide to see if we can[…]""