mix·er / ˈmiksər/ • n. 1. a machine or device for mixing things. esp. an electrical appliance for mixing foods: a food mixer.2. a person considered in terms of their ability to mix socially with others: media people need to be good mixers.3. a social gathering where people can make new acquaintances.4. a soft drink that can be mixed with alcohol.5. (in sound recording and cinematography) a device for merging input signals to produce a combined output in the form of sound or pictures. ∎ a person who operates such a device: a sound mixer.