To often say far-fetched, nonsensical, erroneous, or ignorant things. Ah, don't listen to him, he's full of bull. My dad is so full of bull, it's embarrassing to listen to him talk to other people sometimes.

slang Full of lies, exaggerations, or nonsense. "Bull" is a shortening of "bullshit." Oh, you can't believe a word that guy says—he's full of bull. Not one bit of snow at all—those meteorologists are full of bull.