The adjective foolish implies a lack of common sense or good judgment or, sometimes, a weakness of mind: a foolish decision; The child seems foolish.Fatuous implies being not only foolish, dull, and vacant in mind, but complacent and highly self-satisfied as well: fatuous and self-important; fatuous answers.Silly denotes extreme and conspicuous foolishness; it may also refer to pointlessness of jokes, remarks, etc.: silly and...