Definition & Meaning of "batshit"in English

What is the origin of the term "batshit" and how is it used?

"batshit" is a slang adjective that appeared in American English in the mid-20th century, combining "bat" with "shit" to create a vivid metaphor for extreme irrationality or craziness, drawing on the idea of bats being erratic or frenzied. It is used to describe people, ideas, or behavior that are extremely irrational, unreasonable, or insane. The term appears in informal speech, writing, and media commentary. It is vulgar but often humorous or hyperbolic, intended to emphasize absurdity or madness rather than insult formally.