The material of the surrounding environment, e.g. solid, liquid, gas, vacuum, or a specific substance such as a solvent.
The materials or empty space through which signals, waves, or forces pass.
A format for communicating or presenting information.
A nutrient substance, commonly a solution or solid, for the growth of cells in vitro.
(usually) A substance, structure, or environment in which living organisms subsist, grow or are cultured.
A means, channel, agency or go-between through which communication, commerce, etc is conveyed or carried on, or by which an aim is achieved.
The materials used to finish a workpiece using a mass finishing or abrasive blasting process.
(countable) A liquid base which carries pigment in paint.
A means of expression, in the arts, such as a material (oil, pastel, clay, etc) or method or style (expressionism, jazz, etc).
(countable) The mean or middle term of a syllogism, that by which the extremes are brought into connection.
(countable) Someone who supposedly conveys information from the spirit world.
(countable) A middle place or degree.
(countable, dated) An average; sometimes the mathematical mean.
Anything of a middle rank or position.

(not-comparable, noun-from-verb, obsolete) Arithmetically average.
(not-comparable, noun-from-verb) Of intermediate size, degree, amount etc.
(not-comparable, noun-from-verb) Of meat, cooked to a point greater than rare but less than well done; typically, so the meat is still red in the centre.
(especially, not-comparable, noun-from-verb) That is medium (the manufactured size).

To a medium extent.