or O·toe

[ oh-toh ]
/ ˈoʊ toʊ /
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noun, plural O·tos, (especially collectively) O·to.

a member of a Siouan-speaking tribe of North American Indians who formerly inhabited the lower Missouri River basin and now live in Oklahoma.



In effect, this quiz will prove whether or not you have the skills to know the difference between “affect” and “effect.”
Question 1 of 7
The rainy weather could not ________ my elated spirits on my graduation day.

Definition for Oto (2 of 2)


a combining form meaning “ear,” used in the formation of compound words: otology.
Also especially before a vowel, ot-.

Origin of oto-

<Greek ōto-, combining form of oûsear1
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021


What does oto- mean?

Oto- is a combining form used like a prefix meaning “ear.” It is often used in medical terms, especially in anatomy and pathology.

Oto- comes from the Greek oûs, meaning “ear.” Related to the Greek oûs is English’s own word ear; so is the Latin word for ear, auris, which is the ultimate source of such words as aural. Learn more about oûs at our entry for otic, an adjective used in anatomy meaning “of or relating to the ear.”

What are variants of oto-?

When combined with words or word elements that begin with a vowel, oto- becomes ot-, as in otitis.

Examples of oto-

One example of a medical term that features oto– is otopathy, “a disease of the ear.”

If you’ve been listening, you know that oto- means “ear.” The combining form -pathy is ultimately from the Greek pathos, meaning “suffering, sensation.” It can be used in compound words to indicate “disease.” So, otopathy literally means “ear disease.”

What are some words that use the combining form oto-?

What are some other forms that oto- may be commonly confused with?

Break it down!

Rhinoplasty is plastic surgery of the nose. Blepharoplasty is plastic surgery of the eyelid. What is the medical term for plastic surgery of the ear?

British Dictionary definitions for Oto


before a vowel ot-

combining form

indicating the earotitis; otolith
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

Medical definitions for Oto



The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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