The word "dummy" can refer to a model or representation of a real object that is used for demonstration or practice. It is often used in various contexts, such as in education, where a dummy might be a practice tool, or in products where a dummy version is used for marketing or display purposes. Additionally, it can also mean a person who is perceived as lacking intelligence or being foolish.
The word "dummy" has its roots in the late 18th century, likely derived from the word "dum" which means mute in Middle English. It originally referred to a silent person or a person pretending to be unable to speak.