Medium may mean:

• Recording medium, a physical material that holds information expressed in any of the existing recording formats
• Medium (spirituality), a person who claims to serve as an intermediary between the living and the dead
• Medium of instruction, the language used to educate in
• Average, the sum of all the members of the set divided by the number of items in the set
• A format or material for expression, such as "the medium of painting" or "the medium of dance"

In science:

• Medium (optics), material through which waves propagate
• Processing medium, in industrial engineering, a material that plays a role in manufacturing processes
• Transmission medium, in physics, any material substance which can propagate waves or energy
• Growth medium,
  
  
  
  in biotechnology, an object in which microorganisms or cells in experience growth
• Interplanetary medium, in astronomy, material which fills the solar system
• Interstellar medium, in astronomy, the matter and energy content that exists between the stars within a galaxy
• Excitable medium, a nonlinear dynamical system which has the capacity to propagate a wave
• Solvent in chemistry

In fiction:

• Medium (TV series), a 2005–2006 television series about a research medium for a district attorney's office
• The Medium, an opera by Gian-Carlo Menotti

See also

• Media (disambiguation)

Medium Media メディア (媒体) Media Medium Medium 載體