1. Color: Dun is a light to dark brown color often seen in horses, but it can also describe other animals like cattle or even some fabrics. It can range from a yellowish-brown to a reddish-brown and often has a black or dark mane and tail.
2. Old English word: "Dun" can also be an archaic word meaning "hill" or "mountain." This usage is mostly seen in place names like "Dunsmuir" or "Dunwich."
3. Slang: In some contexts, "dun" can be used as slang for "stupid" or "unintelligent." However, this usage is considered offensive and outdated.
4. Verb: "Dun" can also be used as a verb meaning "to press for payment" or "to demand payment". This usage is often associated with debt collectors or creditors.
To understand what "dun" means in a specific context, you need to consider the surrounding words and phrases. For example, if you hear "a dun mare" it is likely referring to the horse's color. However, if you see a sign that reads "Dun's Diner" it likely refers to the place name.
Please provide me with more context so I can give you a more precise explanation!