From Longman Dictionary of Contemporary Englishaetherae‧ther /ˈiːθə $ -ər/ noun [uncountable] MHHPan old spelling of ether (=the air or sky)
Examples from the Corpus
aether• Maxwell's electromagnetic theory involved an aether occupying all space, whereas Einstein's radical recasting of it eliminated the aether.• All celestial objects in the super-lunar region were made of an incorruptible element called aether.• That was no problem nowadays, books travelled the aether like light and sound.• It is as dead as phlogiston and the universal aether. 