O and O

or O&O

[oh uh nd oh]


  1. a combining form meaning “egg,” used in the formation of compound words: oogamous.

Origin of oo-

< Greek ōio-, combining form of ōión egg1


or o·o, o’·o

noun, plural o-os.
  1. any of several species of Hawaiian honey eaters of the genus Moho, especially the extinct M. nobilis, of the island of Hawaii, that had black plumage and two tufts of yellow plumes used to make ceremonial robes for the Hawaiian kings.

Origin of o-o

First recorded in 1885–90, o-o is from the Hawaiian word ʿōʿō
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for oo

Historical Examples of oo

British Dictionary definitions for oo



combining form
  1. egg or ovumoosperm

Word Origin for oo-

from Greek ōion egg 1
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 oo


word-forming element meaning "egg, eggs," from Greek oon "egg," cognate with Latin ovum, Old Norse egg (see egg (n.)).

Online Etymology Dictionary, © 2010 Douglas Harper

oo in Medicine


  1. Egg; ovum:oogenesis.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.