Dumb blonde is an unkind stereotype. Dumb blonde is an unkind stereotype. The definition of a stereotype is a well-known idea or image of a person or idea that is held by a number of people. An example of stereotype is that blonde-haired women are dumb.Stereotype is defined as to attach an idea or image to a person who belong to a particular group.he definition of a stereotype is a well-known idea or image of a person or idea that is held by a number of people.