Webster's Revised Unabridged Dictionary -- Volume DE

1. That branch of philological science which treats of the history of words, tracing out their origin, primitive significance, and changes of form and meaning.

2. That part of grammar which relates to the changes in the form of the words in a language; inflection.

Et"y·mon (?), n.; pl. E. Etymons (#), Gr. Etyma (#). [L., fr. Gr. ετυμον the true literal sense of a word according to its derivation, an etymon, fr. ? true, real, prob, akin to Skr. sotya, E. sooth. See Sooth.]

1. An original form; primitive word; root.

2. Original or fundamental signification. [R.]

Given as the etymon or genuine sense of the word.
Coleridge.

E·typ"ic·al (?), a. [Pref. e- + typical.] (Biol.) Diverging from, or lacking conformity to, a type.

Eu (?). [Gr. ? well, orig. neut. of ? good; prob. connected with Skr. su, from the same root as E. is; or with Skr. vasu good, prob. fr. the same root as E. was.] A prefix used frequently in composition, signifying well, good, advantageous; -- the opposite of dys-.

Eu·cai"rite (?), n. [Gr. ? seasonable, opportune; ? well, good + ? season.] (Min.) A metallic mineral, a selenide of copper and silver; -- so called by Berzelius on account of its being found soon after the discovery of the metal selenium.

Eu"ca·lyn (ū"k·lĭn), n. (Chem.) An unfermentable sugar, obtained as an uncrystallizable sirup by the decomposition of melitose; also obtained from a Tasmanian eucalyptus, -- whence its name.

Eu`ca·lyp·tol (?), n. [Eucalyptus + L. oleum oil.] (Chem.) A volatile, terpenelike oil extracted from the eucalyptus, and consisting largely of cymene.

Eu`ca·lyp"tus (?), n. [NL., from GR. ? well, good + ? covered. The buds of Eucalyptus have a hemispherical or conical covering, which falls off at anthesis.] (Bot.) A myrtaceous genus of trees, mostly Australian. Many of them grow to an immense height, one or two species exceeding the height even of the California Sequoia.