Horseshit, a word we use to describe something as nonsense, rubbish, or bogus, has various synonyms. Some common ones include baloney, bunk, bullshit, crap, hogwash, malarkey, rubbish, and poppycock. Other more colorful options include horse-feathers, cow-poop, twaddle, gobbledygook, piffle, hooey, and tommyrot.
While all of these words share the same basic meaning, they each have slightly different connotations. For instance, "bunk" and "hogwash" tend to suggest something that is false or ridiculous, while "poppycock" and "piffle" often suggest something trivial or insignificant. Regardless of which word you use, they all convey a sense of disbelief, which makes them useful in a wide range of contexts.