The word "idiot" is often used to describe a person who is perceived to lack intelligence or common sense. It is generally considered a derogatory term and can be used in both serious and joking contexts. The term suggests a deficiency in cognitive ability or poor judgment.
The word "idiot" comes from the Latin word "idiota," which means a private citizen or layperson, derived from the Greek "idiotes," meaning a person lacking professional skill or knowledge. Over time, it evolved to imply a lack of intelligence.