executive order.


a combining form meaning “early,” “primeval,” used in the formation of compound words: Eocene; eohippus.

Origin of eo-

< Greek, combining form of ēṓs (Attic héōs) dawn; akin to east, Aurora


ex officio.

eo ipso

[ey-oh ip-soh; English ee-oh ip-soh]

adverb Latin.

by that very fact.

eo nomine

[ey-oh noh-mi-ne; English ee-oh nom-i-nee]

adverb Latin.

by that name.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for eo


Examples from the Web for eo

Historical Examples of eo

British Dictionary definitions for eo


combining form

early or primevalEocene; eohippus

Word Origin for eo-

from Greek, from ēōs dawn


abbreviation for

ex officio
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for eo


word-forming element used from mid-19c. (first in Eocene) in compound words formed by earth-scientists and meaning "characterized by the earliest appearance of," from Greek eos "dawn," from PIE *aus-, cognate with Modern English east (q.v.). Piltdown Man, before exposed as a fraud, was known as Eoanthropus.

Online Etymology Dictionary, © 2010 Douglas Harper