medium

American  

[mee-dee-uhm] / ˈmi di əm /

noun

media, plural mediums plural

1. a middle state or condition; mean.

2. something intermediate in nature or degree.

3. an intervening substance, as air, through which a force acts or an effect is produced.

4. the element that is the natural habitat of an organism.

5. surrounding objects, conditions, or influences; environment.

6. an intervening agency, means, or instrument by which something is conveyed or accomplished.

   Words are a medium of expression.

7. one of the means or channels of general communication, information, or entertainment in society, as newspapers, radio, or television.

8. Biology. the substance in which specimens are displayed or preserved.

9. Also called culture medium.  Bacteriology. a liquid or solidified nutrient material suitable for the cultivation of microorganisms.

10. a person through whom the spirits of the dead are alleged to be able to contact the living.

11. Fine Arts.

    1. Painting. a liquid with which pigments are mixed.

    2. the material or technique with which an artist works.

       the medium of watercolor.

12. a size of printing paper, 18½ × 23½ inches (47 × 60 centimeters) in England, 18 × 23 to 19 × 25 inches (46 × 58 to 48 × 64 centimeters) in America.

13. Chiefly British. a size of drawing or writing paper, 17½ × 22 inches (44 × 56 centimeters).

14. Also called medium strip.  Midland U.S. median strip.

15. Movies, Television. in medium, with the principal actors in the middle distance.

    The scene was shot in medium.

---

adjective

1. about halfway between extremes, as of degree, amount, quality, position, or size.

   Cook over medium heat. He is of medium height.

   Synonyms:

   middling, mean, average

medium British  

/ ˈmiːdɪəm /

adjective

1. midway between extremes; average

   a medium size

2. (of a colour) reflecting or transmitting a moderate amount of light Compare light 1 dark

   a medium red

---

noun

1. an intermediate or middle state, degree, or condition; mean

   the happy medium

2. an intervening substance or agency for transmitting or producing an effect; vehicle

   air is a medium for sound

3. a means or agency for communicating or diffusing information, news, etc, to the public

   television is a powerful medium

4. a person supposedly used as a spiritual intermediary between the dead and the living

5. the substance in which specimens of animals and plants are preserved or displayed

6. biology short for culture medium

7. the substance or surroundings in which an organism naturally lives or grows

8. art

   1. the category of a work of art, as determined by its materials and methods of production

      the medium of wood engraving

   2. the materials used in a work of art

9. any solvent in which pigments are mixed and thinned

10. any one of various sizes of writing or printing paper, esp 18 1/ 2 by 23 1/ 2 inches or 17 1/ 2 by 22 inches ( small medium )

medium Scientific  

/ mē′dē-əm /

media plural

1. A substance, such as agar, in which bacteria or other microorganisms are grown for scientific purposes.

2. A substance that makes possible the transfer of energy from one location to another, especially through waves. For example, matter of sufficient density can be a medium for sound waves, which transfer mechanical energy.

3. See more at wave

---

medium Idioms  

1. see happy medium.

---

Usage

See media ¹.

Other Word Forms

Noun Inflected Forms

• media
  plural
• mediums
  plural

Etymology

Origin of medium

First recorded in 1575–85; from Latin: “the middle,” noun use of neuter of medius “middle”; see mid ¹

Explanation

Think of the word medium as something in between. In clothing, we have small, medium, and large; in communications, it's what signals travel through from broadcast to receiver; and in spiritual terms, it’s a person who converses with the dead. The word medium — from the Latin adjective medius, "middle" — has several meanings that all center on the idea of being in between. From the air that carries the broadcast signal, to the person who transmits messages from the dead, to the measurement of the "doneness" of your steak, medium means something that lies between two other points, people, or levels.

Example Sentences

This article originally appeared in slightly different form at Medium.

From Salon • Jun. 13, 2026

The observations were carried out using MIRI's Medium Resolution Spectrometer, an instrument that separates infrared light into its individual wavelengths.

From Science Daily • Jun. 4, 2026

The "hundreds" of vials, labelled Virus Transport Medium, are believed to be among thousands of tonnes of waste dumped over the cliffs at the north of the island.

From BBC • Apr. 30, 2026

Medium and larger-sized producers are bracing for rises in energy prices as contracts are up for renewal, while smaller producers that buy on the spot are already feeling the strain, the federation said.

From The Wall Street Journal • Apr. 1, 2026

The Spirit Medium watched quietly from the shadows.

From "The Ear, the Eye, and the Arm" by Nancy Farmer

Related Words

• channel
• form
• instrument
• mechanism
• tool
• vehicle