noun
ether
An imagined invisible medium filling surrounding space.
In this outdated theory, light travels through an invisible ether.
Etymology
The Greek word names the upper air. Later theories extended it to an unseen substance filling space, preserving the idea of an all-surrounding celestial medium.
More examples
- Early physicists searched for evidence of the ether.
- The old diagram shows planets moving through the ether.
- Her radio message vanishes into the ether.
Forms
ether
Similar words
- medium
- Names any carrier of waves, not specifically the imagined ether.