Jump To:

• 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.

---

CO ² American  

abbreviation

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

2. commanding officer.

3. conscientious objector.

---

Co. ³ American  

Or co.

abbreviation

1. Company.

2. County.

---

c/o ⁴ American  

1. care of.

2. Bookkeeping. carried over.

3. cash order.

---

C/o ⁵ American  

1. care of.

2. Bookkeeping. carried over.

---

C/O ⁶ American  

1. cash order.

2. certificate of origin.

---

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 ).

---

c.o. ⁸ American  

abbreviation

1. care of.

2. carried over.

---

C.O. ⁹ American  

abbreviation

1. cash order.

2. Commanding Officer.

3. conscientious objector.

4. correction officer.

---

CO ¹ British  

abbreviation

1. Commanding Officer

2. Commonwealth Office

3. conscientious objector

4. Colorado

5. Colombia (international car registration)

---

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

---

Co ³ British  

abbreviation

1. (esp in names of business organizations) Company

2. informal and the rest of them

   Harold and co

---

c/o ⁴ British  

abbreviation

1. care of

2. accounting carried over

---

co ⁵ British  

abbreviation

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

2. Colombia

---

Co ⁶ British  

symbol

1. cobalt

---

Co ⁷ British  

abbreviation

1. County

---

Etymology

Origin of co-

from Latin, reduced form of _com-

Example Sentences

“The thing we are most concerned about is the AI capex cycle,” said Brad Conger, chief investment officer at Hirtle & Co.

From MarketWatch • Jun. 8, 2026

The complaint identifies the company as Faraz Pardaz Rayaneh Co.

From Los Angeles Times • Jun. 4, 2026

It licenses technology from the largest battery maker in the world, Contemporary Amperex Technology Co.

From Barron's • Jun. 3, 2026

Victoria’s Secret’s current ticker is “VSCO,” a nod to its full corporate designation: Victoria’s Secret & Co.

From The Wall Street Journal • May 21, 2026

"Co back to your bedchamber, sweet Jonquil," he whispered.

From "A Clash of Kings" by George R.R. Martin