Emily Dickinson Lexicon

E'THER, n. [L. æther; Gr. αιθηρ, αιθω, to burn, to shine; Eng. weather; Sax. wæder, the air; D. weder; G. wetter; Sw. väder.]

1. A thin, subtil matter, much finer and rarer than air, which, some philosophers suppose, begins from the limits of the atmosphere and occupies the heavenly space. Newton. There fields of light and liquid ether flow. Dryden.
2. In chimistry, a very light, volatile and inflammable fluid, produced by the distillation of alcohol, or rectified spirit of wine, with an acid. It is lighter than alcohol, of a strong sweet smell, susceptible of great expansion, and of a pungent taste. It is so volatile, that when shaken it is dissipated in an instant. Encyc. Fourcroy.