First recorded in 1861; named after G. S. Ohm
An ohm is a unit of electricity — or more specifically, a unit of electrical resistance. The resistance of good electrical conductors, like copper, is measured in ohms. When it comes to electricity, there are many ways to measure it, including amps of current and volts of voltage. Ohms specifically measure the amount of resistance in an electrical current, an idea that's easiest to understand in terms of plumbing. Picture water flowing through a pipe; the water pressure is the voltage, the rate at which it flows is the current, and the size of the pipe is the resistance. Ohm is named for Georg S. Ohm, the physicist who discovered the relationship between current, voltage, and resistance.
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Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Because USB cables are terrible – just think about the number of bell wire USB cables with 10k ohm resistance.
From The Verge ● Mar. 8, 2022
Sometimes I just let the water pummel the top of my head and listen to the ohm of the fan’s whir, losing myself in the hug of its hum.
From Washington Post ● Oct. 27, 2021
"For illustration, here are some shorties which we'd call real $7 words, and wouldn't use here at this time without explanation: adit, erg, ergo, ohm, gloze, cozen, griff, modal, mure, snash, viable."
From Time Magazine Archive
They had discovered the X ray, the cathode ray, the electron, and radioactivity, invented the ohm, the watt, the Kelvin, the joule, the amp, and the little erg.
From "A Short History of Nearly Everything" by Bill Bryson
Volt, vōlt, n. the unit of electro-motive force now in universal use among electricians, defined legally in terms of the ohm and ampere.—adj.
From Chambers's Twentieth Century Dictionary (part 4 of 4: S-Z and supplements) by Various
“We design our products and services to protect people’s privacy because only DNA is harder to anonymize than human movements,” the company’s website says, quoting Georgetown law and privacy expert Paul Ohm.
From The Wall Street Journal ● Jul. 21, 2026
Although the film never comes out and says it, Ohm was possibly conceived on these unhallowed grounds, so maybe he was just born cursed.
From Los Angeles Times ● Apr. 30, 2026
Ayres’ lawyer, Eugene Ohm, sought a sentence of probation without any jail time.
From Seattle Times ● Sep. 22, 2022
The companies, Best Electricity Supply, Ohm Energy, UGS Energy, SilverCloud Energy and iSwitch supplied around 9% of Singapore's electricity consumers, with their closures a setback to the country's power market liberalisation.
From Reuters ● Dec. 9, 2021
The unit of resistance is known as an Ohm.
From Electric Bells and All About Them A Practical Book for Practical Men by S. R. Bottone
The units of impedance are ohms, and its effect on the circuit is as you might expect: the greater the impedance, the smaller the current.
From Textbooks ● Aug. 12, 2015
Find the current if the resistance is 12 ohms.
From Textbooks ● Feb. 13, 2015
Unfortunately, when you buy a resistor, you can’t get one that is exactly 1000 ohms; rather, it is guaranteed to be only within 10 percent of that value.
From Salon ● Feb. 16, 2013
Electricity is sold in kilowatt-hours but electricity terminology spans other units like volts, amperes, and ohms.
From Slate ● Oct. 14, 2011
For 3 ohms it takes three times as much to give one ampere.
From Letters of a Radio-Engineer to His Son by John Mills
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
