The definition of a medium is something that helps an effect to happen, or is a singular form of media.(noun)
Medium is defined as something in the middle or in-between.(adjective)
An example of medium is a shirt that's bigger than small and smaller than large.
See medium in Webster's New World College Dictionary
Origin: L, the middle, neut. of medius: see mid
See medium in American Heritage Dictionary 4
noun pl. me·di·a (-dē-ə) or me·di·ums
Origin: , from
Origin: neuter of medius, middle; see medhyo- in Indo-European roots. Usage Note: The etymologically plural form media is often used as a singular to refer to a particular means of communication, as in The Internet is the most exciting new media since television. Many people regard this usage as incorrect, preferring medium in such contexts. • People also use media with the definite article as a collective term to refer not to the forms of communication themselves so much as the communities and institutions behind them. In this sense, the media means something like “the press.” Like other collective nouns, it may take a singular or plural verb depending on the intended meaning. If the point is to emphasize the multifaceted nature of the press, a plural verb may be more appropriate: The media have covered the trial in a variety of formats. Frequently, however, media stands as a singular noun for the aggregate of journalists and broadcasters: The media has not shown much interest in covering the trial. This development of a singular media parallels that of more established words such as data and agenda, which are also Latin plurals that have acquired a singular meaning. • The singular medium cannot be used as a collective noun for the press. The sentence No medium has shown much interest in covering the issue, would suggest that the lack of interest is in the means of communication itself rather than in its practitioners.
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