Eth"ene (?), n. (Chem.) Ethylene; olefiant gas.
E*then"ic (?), a. (Chem.) Pertaining to, derived from. or resembling, ethene or ethylene; as, ethenic ether.
Eth"e*nyl (?), n. [Ethene + - yl.] (Chem.) (a) A trivalent hydrocarbon radical, CH3.C. (b) A univalent hydrocarbon radical of the ethylene series, CH2:CH; -- called also vinyl. See Vinyl.
E`the*os"to*moid (?), a. [NL. etheostoma name of a genus + -oid.] (Zoöl.) Pertaining to, or like, the genus Etheostoma. -- n. Any fish of the genus Etheostoma and related genera, allied to the perches; -- also called darter. The etheostomoids are small and often bright-colored fishes inhabiting the fresh waters of North America. About seventy species are known. See Darter.
E"ther ("thr), n. [L. aether, Gr. a'iqh`r, fr. a'i`qein to light up, kindle, burn, blaze; akin to Skr. idh, indh, and prob. to E. idle: cf. F. éther.] [Written also æther.] 1. (Physics) A medium of great elasticity and extreme tenuity, supposed to pervade all space, the interior of solid bodies not excepted, and to be the medium of transmission of light and heat; hence often called luminiferous ether.