medium

me·di·um

noun \ˈmēd-ē-əm\

plural mediums or me·dia \-ē-ə\

Definition of MEDIUM

1

: a means of effecting or conveying something: as a : a substance regarded as the means of transmission of a force or effect b : a surrounding or enveloping substance

2

plural media a : a nutrient system for the artificial cultivation of cells or organisms and especially bacteria b : a fluid or solid in which organic structures are placed (as for preservation or mounting)