The phrase "pure bullshit" is an idiomatic expression that means something is completely false, untrue or a blatant lie. It's often used to describe a statement or claim that has no basis in reality and is intended to deceive others. The term "bullshit" itself is a vulgarism that refers to nonsensical or foolish talk or writing, typically as a means of obtaining advantage or avoiding commitment. In other words, it's an expression used to describe something that is without substance, relevance, or value.