What do you picture if you close your eyes and think of the word bullshit? A bull, the animal, shitting.
The worst would be someone stepping on or into it, disgusting as it may sound; most of us would have experienced something similar.
So what's the Bullshit Story?
The Bull part in the word meant to lie or fraud.
"Bull", meaning nonsense, dates from the 17th century. The word "bull" itself may have derived from the Old French bole meaning "fraud, deceit". At the same time, the term "bullshit" was used as early as 1915 in British and American slang and came into widespread usage only during World War II.
The Shit part in the word meant to excrete or expel.
It's a contraction of "bull" (lies) and "shit" (excrement). Thus putting the two, "Bullshit" means simply stating a lie.
Nowadays, people say "bullshit" to say they feel it's either kidding or stating a lie (it's not a bad word). We assume they're only abbreviating as bullshit to make it seem less vulgar, but this is the older word.