# dark matter

> English word · Noun

## Definitions
1. Matter which cannot be detected by its radiation but whose presence is inferred from gravitational effects.
2. Matter which has mass but which does not readily interact with normal matter except through gravitational effects.
3. Unclassified or poorly understood genetic material.

## Etymology
Calque of German Dunkle Materie, from dunkel (“dark”) and Materie (“matter”). Coined by Swiss astronomer Fritz Zwicky in German in 1933, to account for the apparent mass needed to account for galaxy clusters, where the mass of luminous matter did not add up to enough of a gravitational effect, inferring nonluminous matter must exist to account for the missing mass. The term gained new popularity due to the missing mass found in galaxies to account for galaxy rotation curves discovered by Vera Rubin in research published in English in the 1970s.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/dark-matter