"Only an idiot would fail this exam.; After failing a hat-trick of exams, the teacher called him an idiot."
2.NounA person who makes stupid decisions; a fool.
"He thought people who don't like cricket are idiots. He later got into fights with people who like football.; We think that people who cycle without a helmet are idiots."
3.NounA person of the lowest intellectual standing, a person who lacks the capacity to develop beyond the mental age of a normal four-year-old; a person with an IQ below 30.