I. -ˈmē-dē-ə adjective
Date: 1962
: using, involving, or encompassing several media
a multimedia approach to learning
II. noun plural but singular or plural in construction
Date: 1967
: a technique (as the combining of sound, video, and text) for expressing ideas (as in communication, entertainment, or art) in which several media are employed ; also : something (as software) using or facilitating such a technique