Bullshit (also bullcrap) is a common English expletive which may be shortened to the euphemism bull or the initialism BS. In British English, "bollocks" is a comparable expletive, although bullshit is commonly used in British English. It is a slang profanity term meaning either (literally) bovine excrement or, more commonly, "nonsense", especially in a rebuking response to communication or actions viewed as deceiving, misleading, disingenuous or false. As with many expletives, the term can be used as an interjection or as many other parts of speech, and can carry a wide variety of meanings.
It can be used either as a noun or as a verb. While the word is generally used in a deprecating sense, it may imply a measure of respect for language skills, or frivolity, among various other benign usages. In philosophy, Harry Frankfurt, among others, analyzed the concept of bullshit as related to but distinct from lying.
Outside of the philosophical and discursive studies, the everyday phrase bullshit conveys a measure of dissatisfaction with something or someone, but does not generally describe any role of truth in the matter.