Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

  

CO

noun [C]
 
 
/ˌsiːˈəʊ/ US  /-ˈoʊ/

Definition

abbreviation for Commanding Officer: a person in charge of a military unitGeneral ranks in the armed forces
(Definition of CO noun from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)

“CO” in other dictionaries

Word of the Day

a cloud on the horizon

something which threatens to cause problems or unhappiness in the future

Word of the Day

Blog

Read our blog about how the English language behaves.

Learn More

New Words

Find words and meanings that have just started to be used in English, and let us know what you think of them.

Learn More