Den may refer to:
Denmark (/ˈdɛnmɑːrk/; Danish: Danmark [ˈd̥ænmɑɡ̊]), officially the Kingdom of Denmark, is a Scandinavian country in Europe and a sovereign state.
Denver (/ˈdɛnvər/), officially the City and County of Denver, is the capital and most populous municipality of the U.S.
In computing, a denial-of-service attack (DoS attack) is a cyber-attack where the perpetrator seeks to make a machine or network resource unavailable to its intended users by temporarily or indefinitely disrupting services of a host connected to the Internet.
Denver International Airport (IATA: DEN, ICAO: KDEN, FAA LID: DEN), often referred to as DIA, is an airport in Denver, Colorado, United States.
A dental implant (also known as an endosseous implant or fixture) is a surgical component that interfaces with the bone of the jaw or skull to support a dental prosthesis such as a crown, bridge, denture, facial prosthesis or to act as an orthodontic anchor.