[count] a small object (such as a tag, pin, or metal shield) that is worn or held up by a person so that it can be easily seen, that has writing (such as a person's name) and often a picture on it, and that shows who the person is

a cloth patch that can be sewn onto clothing and that is awarded to a person (such as a Boy Scout or Girl Scout) for doing something

Brit :1button

something that represents or is a sign of something else