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• Co
  Co

  cobalt.
• CO
  CO

  abbreviation

  Colorado (approved especially for use with zip code).
• Co.
  Co.

  abbreviation

  Company.
• c/o
  c/o

  care of.
• C/o
  C/o

  care of.
• C/O
  C/O

  cash order.
• co-
  co-

  variant of com- before a vowel, h, and gn: coadjutor; cohabit; cognate . The prefix co- now productively forms new words from bases beginning with any sound (co-conspirator; co-manage; coseismic ), sometimes with the derived sense “auxiliary, subsidiary” (coenzyme; copilot ), and, in mathematics and astronomy, with the sense “complement” (codeclination ).
• c.o.
  c.o.

  abbreviation

  care of.
• C.O.
  C.O.

  abbreviation

  cash order.
• co
  co

  abbreviation

  a commercial company (used with a country domain name)

Co

¹ American  

Symbol, Chemistry.

1. cobalt.

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CO ² American  

abbreviation

1. Colorado (approved especially for use with zip code).

2. commanding officer.

3. conscientious objector.

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Co. ³ American  

Or co.

abbreviation

1. Company.

2. County.

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c/o ⁴ American  

1. care of.

2. Bookkeeping. carried over.

3. cash order.

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C/o ⁵ American  

1. care of.

2. Bookkeeping. carried over.

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C/O ⁶ American  

1. cash order.

2. certificate of origin.

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co- ⁷ American  

1. variant of com- before a vowel, h, and gn: coadjutor; cohabit; cognate . The prefix co- now productively forms new words from bases beginning with any sound (co-conspirator; co-manage; coseismic ), sometimes with the derived sense “auxiliary, subsidiary” (coenzyme; copilot ), and, in mathematics and astronomy, with the sense “complement” (codeclination ).

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c.o. ⁸ American  

abbreviation

1. care of.

2. carried over.

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C.O. ⁹ American  

abbreviation

1. cash order.

2. Commanding Officer.

3. conscientious objector.

4. correction officer.

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CO ¹ British  

abbreviation

1. Commanding Officer

2. Commonwealth Office

3. conscientious objector

4. Colorado

5. Colombia (international car registration)

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co- ² British  

prefix

1. together; joint or jointly; mutual or mutually

   coproduction

2. indicating partnership or equality

   cofounder

   copilot

3. to the same or a similar degree

   coextend

4. (in mathematics and astronomy) of the complement of an angle

   cosecant

   codeclination

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Co ³ British  

abbreviation

1. (esp in names of business organizations) Company

2. informal and the rest of them

   Harold and co

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c/o ⁴ British  

abbreviation

1. care of

2. accounting carried over

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co ⁵ British  

abbreviation

1. a commercial company (used with a country domain name)

2. Colombia

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Co ⁶ British  

symbol

1. cobalt

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Co ⁷ British  

abbreviation

1. County

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Etymology

Origin of co-

from Latin, reduced form of _com-

Example Sentences

See Examples For:

Co CO Co. c/o C/o C/O co- c.o. C.O. co

"Discussions are ongoing and there can be no certainty that a transaction will be entered into. Rothschild & Co is advising the board of Goodwin on the strategic review."

From BBC ● Aug. 7, 2026

The company is listed on the Abu Dhabi Securities Exchange and is part of state-owned oil giant Abu Dhabi National Oil Co.

From The Wall Street Journal ● Aug. 5, 2026

In this process, fine WC and Co powders are compressed under high pressure and heated in sintering machines.

From Science Daily ● Aug. 4, 2026

For years after he started building trucks, Ramirez and his cousin also ran a taco truck called LA Tacos & Co.

From Los Angeles Times ● Jul. 25, 2026

Just inside, a note identifying the publisher as R. L. Polk & Co, the name everyone uses when they talk about the compendium of businesses and people.

From "The Brightwood Code" by Monica Hesse

CO chondrites, also called carbonaceous chondrites of the Ornans class, represent only a very small portion of that group.

From Science Daily ● Jul. 19, 2026

Pennington's hometown was Glendale, Kentucky, and he was assigned to the 1st Space Battalion, 1st Space Brigade out of Fort Carson, CO.

From Barron's ● Mar. 10, 2026

“What Eric voted for was a resolution to condemn a horrific antisemitic attack in Boulder, CO that killed Karen Diamond, an 82-year old grandmother,” a campaign spokesman said in a statement.

From Los Angeles Times ● Jan. 28, 2026

The investigation by HSE gas safety experts found one of the boilers to be leaking CO in the school's plant room.

From BBC ● Nov. 20, 2025

Here, our bon voyage had a definite CO flavor: “You’re the zookeeper now,” said Officer Luther.

From "Newjack: Guarding Sing Sing" by Ted Conover

They include PepsiCo and the spice merchant McCormick & Co., which both cited nontariff price increases as a target of the refunds.

From Los Angeles Times ● Aug. 6, 2026

The building to be occupied by Innocean was completed in 1930 as a bus manufacturing plant for Pickwick Stage Co., a California operator that became part of Greyhound Lines.

From Los Angeles Times ● Aug. 5, 2026

The Japanese company said in May that it planned to form a joint venture with Taiwan Semiconductor Manufacturing Co. to develop and produce next-generation image sensors.

From The Wall Street Journal ● Jul. 31, 2026

It also said it had sold off the trademark and other assets related to Maple Street Biscuit Co. a fast-casual chain it had owned, and said it would close that chain’s 16 remaining locations.

From MarketWatch ● Jul. 28, 2026

Behind me, the kitchen windows are propped open with Sears, Roebuck & Co. catalogues.

From "The Help" by Kathryn Stockett

For some time afterward, envelopes containing dollar bills made their way to “Viva Superstar, c/o The Chelsea Hotel.”

From New York Times ● Apr. 28, 2023

By filling out a form online or downloading the claim form and then mailing it to Facebook Consumer Privacy User Profile Litigation, c/o Settlement Administrator, 1650 Arch Street, Suite 2210, Philadelphia, PA 19103.

From Los Angeles Times ● Apr. 18, 2023

Donations may be made online at www.miap.us or mailed to Missing in America Project, c/o John Hundahl, 1507 S. Quillan St., Kennewick, WA 99338.

From Seattle Times ● Apr. 10, 2018

From lesser-known labels such as Vetements, Off-White c/o Virgil Abloh and Yang Li to global companies such as Dries Van Noten, Rick Owens, Prada and Maison Margiela, luxury now comes with unfinished hems.

From Washington Post ● Apr. 7, 2015

You may return expense advance to Lovelace Foundation c/o me.

From "Women in Space" by Karen Bush Gibson

As I have only four weeks in which to complete my work here and get to London a 'collect reply by cable to C/o Colonel Sellheim, Australian Intermediate Base, Cairo, would greatly oblige.

From Gallipoli Diary, Volume 2 by Hamilton, Ian, Sir

The box was a gift from Felix Hoffmann, chief curator at C/O Berlin gallery, which he made in 2013.

From The Wall Street Journal ● Nov. 3, 2015

His personal project, Anniversaries, will be exhibited at C/O Berlin from June 20 to August 16.

From Time ● Jun. 5, 2015

Freeze frame … the C/O Gallery focuses on photography.

From The Guardian ● Aug. 17, 2011

A decade later, the scene has since caught up — though C/O remains at the epicenter, having shown the likes of Robert Frank and Nan Goldin.

From New York Times ● Dec. 26, 2010

C/O was thus founded to rectify Berlin’s undervaluing of art photography.

From New York Times ● Dec. 26, 2010

Professor Rob Ogden has been closely involved in setting up the project and is co- founder of the organisation Trace, which promotes the use of forensic science in wildlife law enforcement.

From BBC ● Feb. 19, 2026

“Happy Father’s Day to my baby daddy and rad co- parent,” she captioned a pair of family photos.

From Los Angeles Times ● Nov. 4, 2025

He added, "We are committed to advancing our efforts to transform the prospect of a universal treatment, capable of controlling co- and serial infections of respiratory viruses and bacteria, into a reality."

From Science Daily ● Mar. 18, 2024

“The Yamnaya are extraordinary,” says the study’s co- author Volker Heyd, an archaeologist at the University of Helsinki.

From Scientific American ● Mar. 3, 2023

NOTE.—The forms co-, col-, com-, and cor-, are euphonic variations of con-.

From New Word-Analysis by William Swinton

It seemed significant that our hero came clean about killing his c.o., the darkest element of Don Draper’s origin story, after initially lying about his rank.

From Slate ● May 11, 2015

A New Yorker of draft age, Seeger claimed exemption as a conscientious objector, but he was an unusual sort of c.o.

From Time Magazine Archive

Last week he got the Board to order the trial of a c.o. for incompetence.

From Time Magazine Archive

He had said that his "humanitarian beliefs" forbade him to bear arms, but lost an appeal to the President for classification as a c.o.

From Time Magazine Archive

The Selective Service Act makes it unmistakably clear that no one is to be exempted from the draft as a c.o. unless he holds to a "belief in a relation to a Supreme Being."

From Time Magazine Archive

Alec Ginsberg, a fourth-generation pharmacist who owns C.O.

From MarketWatch ● Jul. 23, 2026

Instead, it was “so many people screaming, screaming to talk to each other. Screaming for assistance: ‘Yo, C.O., my toilet flooded.

From Slate ● May 19, 2025

Loco told him that it had all been pretty bad, and the C.O. talked to Loco about his own experience.

From New York Times ● Apr. 6, 2021

The C.O. sat glued to this chair, looking bored.

From Salon ● Aug. 8, 2020

“It looks like the troops are goldbricking again and the C.O. needs to revamp the work detail. Let’s cut the idle chitchat and police up the area.”

From "The Great Santini" by Pat Conroy

This was supposed to be the Netherlands' time, as Johan Cruyff and co dazzled throughout the tournament with their revolutionary Total Football approach.

From BBC ● Jul. 17, 2026

Football fever is growing in the States with the co hosts looking an organised side.

From BBC ● Jul. 4, 2026

According to co author Brian Metzger of Columbia University, it is possible that two newly formed neutron stars could spiral inward and collide, producing a kilonova that emits gravitational waves.

From Science Daily ● Apr. 24, 2026

Winning cures most ills, and there is a calculated gamble from Gould, Key and co that England have a good chance of success over the coming months.

From BBC ● Mar. 20, 2026

D i s co m f It/d I s co m Fo RT.

From "Woe Is I" by Patricia T. O'Conner