CI | Meaning, Definition In Cambridge English Dictionary

Meaning of CI in English CInoun [ C ] mainly US uk /ˌsiːˈaɪ/ us /ˌsiːˈaɪ/ Add to word list Add to word list abbreviation for confidential informant: a person who secretly gives information to the police about criminal activity: She worked for years as an active CI, and still called occasionally with tips on various cases. Information provided by a CI was put before the jury.

• The agent tried for three years to get into one gangster's dope house but never found a CI who could buy from the target.
• Carter's daughter believes there may be a connection between her mother's career as a CI and the murder case.
• Gomez sold 6 Ecstasy tablets to a CI who was wearing a wire.
• "Most times a CI is a person that has been caught doing something illegal and law enforcement has struck a deal with them", he says.

Detection & solving crimes

• all-points bulletin
• ankle bracelet
• ankle tag
• ANPR
• APB
• fingertip search
• forensic
• forensic science
• forensically
• forensics
• private eye
• private investigator
• profiler
• profiling
• psychological profile
• strip search
• supersleuth
• surveil
• take fingerprints
• tighten

See more results » (Definition of CI from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)

CI | Business English

CInoun [ U ]   MARKETING uk us Add to word list Add to word list abbreviation for customer intelligence (Definition of CI from the Cambridge Business English Dictionary © Cambridge University Press) What is the pronunciation of CI?

Translations of CI

in Chinese (Traditional) 秘密線人（confidential informant 的縮寫）… See more in Chinese (Simplified) 秘密线人（confidential informant 的缩写）… See more in Spanish forma abreviada de "confidential informant":, confidente… See more in Portuguese forma abreviada de "confidential informant":, informante confidencial… See more Need a translator?

Get a quick, free translation!

Translator tool

Browse

chutzpah chyme chymotrypsin BETA Chyron CI ciabatta ciao CIB cicada Cambridge Dictionary +Plus

Learn more with +Plus

Create word lists and quizzes for free

Sign up or Log in

More meanings of CI

• CI, at confidential informant
• CI, at customer intelligence

See all meanings

Word of the Day

bleak

UK /bliːk/ US /bliːk/

If a place is bleak, it is empty, and not welcoming or attractive.

About this

Blog

Flavour of the month (Newspaper idioms)

January 28, 2026 Read More

New Words

clip farming February 02, 2026 More new words has been added to list To top AI Assistant Contents EnglishBusinessTranslations AI Assistant {{#displayLoginPopup}} Cambridge Dictionary +Plus

Learn more with +Plus

Sign up for free and get access to exclusive content: Free word lists and quizzes from Cambridge Tools to create your own word lists and quizzes Word lists shared by our community of dictionary fans Sign up now or Log in Cambridge Dictionary +Plus

Learn more with +Plus

Create word lists and quizzes for free Sign up now or Log in {{/displayLoginPopup}} {{#displayClassicSurvey}} {{/displayClassicSurvey}}

• Cambridge Dictionary +Plus
• My profile
• +Plus help
• Log out

AI Assistant Dictionary Definitions Clear explanations of natural written and spoken English English Learner’s Dictionary Essential British English Essential American English Translations Click on the arrows to change the translation direction. Bilingual Dictionaries English–Chinese (Simplified) Chinese (Simplified)–English English–Chinese (Traditional) Chinese (Traditional)–English English–Danish Danish–English English–Dutch Dutch–English English–French French–English English–German German–English English–Indonesian Indonesian–English English–Italian Italian–English English–Japanese Japanese–English English–Norwegian Norwegian–English English–Polish Polish–English English–Portuguese Portuguese–English English–Spanish Spanish–English English–Swedish Swedish–English Semi-bilingual Dictionaries English–Arabic English–Bengali English–Catalan English–Czech English–Gujarati English–Hindi English–Korean English–Malay English–Marathi English–Russian English–Tamil English–Telugu English–Thai English–Turkish English–Ukrainian English–Urdu English–Vietnamese Translate Grammar Thesaurus Pronunciation Cambridge Dictionary +Plus Games {{userName}}

• Cambridge Dictionary +Plus
• My profile
• +Plus help
• Log out

Log in / Sign up English (UK) Change English (UK) English (US) Español Português 中文 (简体) 正體中文 (繁體) Dansk Deutsch Français Italiano Nederlands Norsk Polski Русский Türkçe Tiếng Việt Svenska Українська 日本語 한국어 ગુજરાતી தமிழ் తెలుగు বাঙ্গালি मराठी हिंदी Follow us Choose a dictionary

• Recent and Recommended {{#preferredDictionaries}} {{name}} {{/preferredDictionaries}}
• Definitions Clear explanations of natural written and spoken English English Learner’s Dictionary Essential British English Essential American English
• Grammar and thesaurus Usage explanations of natural written and spoken English Grammar Thesaurus
• Pronunciation British and American pronunciations with audio English Pronunciation
• Translation Click on the arrows to change the translation direction. Bilingual Dictionaries
  • English–Chinese (Simplified) Chinese (Simplified)–English
  • English–Chinese (Traditional) Chinese (Traditional)–English
  • English–Danish Danish–English
  • English–Dutch Dutch–English
  • English–French French–English
  • English–German German–English
  • English–Indonesian Indonesian–English
  • English–Italian Italian–English
  • English–Japanese Japanese–English
  • English–Norwegian Norwegian–English
  • English–Polish Polish–English
  • English–Portuguese Portuguese–English
  • English–Spanish Spanish–English
  • English–Swedish Swedish–English
  Semi-bilingual Dictionaries English–Arabic English–Bengali English–Catalan English–Czech English–Gujarati English–Hindi English–Korean English–Malay English–Marathi English–Russian English–Tamil English–Telugu English–Thai English–Turkish English–Ukrainian English–Urdu English–Vietnamese
• Dictionary +Plus Word Lists

Choose your language English (UK) English (US) Español Português 中文 (简体) 正體中文 (繁體) Dansk Deutsch Français Italiano Nederlands Norsk Polski Русский Türkçe Tiếng Việt Svenska Українська 日本語 한국어 ગુજરાતી தமிழ் తెలుగు বাঙ্গালি मराठी हिंदी Contents

• English   Noun
• Business   Noun

• Translations
• Grammar
• All translations

My word lists

To add CI to a word list please sign up or log in.

Sign up or Log in My word lists

Add CI to one of your lists below, or create a new one.

{{#verifyErrors}}

{{message}}

{{/verifyErrors}} {{^verifyErrors}} {{#message}}

{{message}}

{{/message}} {{^message}}

Something went wrong.

{{/message}} {{/verifyErrors}} {{name}} More Go to your word lists {{#verifyErrors}}

{{message}}

{{/verifyErrors}} {{^verifyErrors}} {{#message}}

{{message}}

{{/message}} {{^message}}

Something went wrong.

{{/message}} {{/verifyErrors}} Tell us about this example sentence: The word in the example sentence does not match the entry word. The sentence contains offensive content. Cancel Submit Thanks! Your feedback will be reviewed. {{#verifyErrors}}

{{message}}

{{/verifyErrors}} {{^verifyErrors}} {{#message}}

{{message}}

{{/message}} {{^message}}

There was a problem sending your report.

{{/message}} {{/verifyErrors}} The word in the example sentence does not match the entry word. The sentence contains offensive content. Cancel Submit Thanks! Your feedback will be reviewed. {{#verifyErrors}}

{{message}}

{{/verifyErrors}} {{^verifyErrors}} {{#message}}

{{message}}

{{/message}} {{^message}}

There was a problem sending your report.

{{/message}} {{/verifyErrors}}