Dude is an American English slang term that is used to refer to anyone.
The term dates back to the 1870s, when it was used to refer to someone who was dressed very well or in a very fashionable manner. However, today the term is very versatile and can be used to refer to a friend or a stranger.
Usually the term can be heard being used to refer to or call the attention of someone. For example, “Dude! Where have you been?” or “Where are you going dude?” However, the term also retains some of its original meaning and is also used in that context, even if not too commonly. For example, “You’re looking like a dude.”
The term is generally used to refer to males; however that is not always the case. It may also be used to refer to a female or in its plural form (dudes) be used to refer to a group of males, or males and females mixed. A female may also be referred to as “dudette”.