Quiz: Remember the definition of mal de mer?


[oh-toh] /ˈoʊ toʊ/
noun, plural Otos (especially collectively) Oto.
a member of a Siouan-speaking tribe of North American Indians who formerly inhabited the lower Missouri River basin and now live in Oklahoma.
Also, Otoe.


a combining form meaning “ear,” used in the formation of compound words:
Also, especially before a vowel, ot-.
< Greek ōto-, combining form of oûs ear1 Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
Cite This Source
British Dictionary definitions for Oto


combining form
indicating the ear: otitis, otolith
Word Origin
from Greek ous, ōt- ear
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
Cite This Source
Oto in Medicine

oto- or ot-
Ear: otology.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
Related Abbreviations for Oto


The American Heritage® Abbreviations Dictionary, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Cite This Source
Encyclopedia Article for Oto

North American Indian people of the Chiwere branch of the Siouan linguistic family, which also includes the closely related Missouri and Iowa tribes. In their historic past the Oto, together with the Iowa and the Missouri, separated from the Ho-Chunk and moved southwest. In 1673, when met by the Jacques Marquette expedition, they were living some distance up the Des Moines River in present-day Iowa. By 1804 they were living near the mouth of the Platte River. In 1830 they ceded all their land in Missouri and Iowa to the United States government and ultimately sold off their remaining land in Kansas and Nebraska. In 1882 they were removed to Indian Territory (present-day Oklahoma)

Learn more about Oto with a free trial on
Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
Cite This Source

Word of the Day

Difficulty index for Oto

Some English speakers likely know this word

Word Value for Oto

Scrabble Words With Friends

Nearby words for oto