noun
bull
BULL/bʊl/
Nonsense or false talk.
His excuse sounds like a lot of bull.

Etymology
Probably continues an older word for false talk. Its relationship to the animal-name is uncertain; modern speakers also use it as a shortening of bullshit.
In context
That's BULL and you KNOW it, you pig-headed old bigot!
that's bull and you know it you need somebody's help