What Does CD9 Mean?

CD9 means "Code 9 (Adult Alert)".

The cyber abbreviation CD9 is typically used with the meaning "Adult Alert" by young people who are undertaking an online activity that they wish to hide from their parents or other adults (e.g., gaming, engaging in dating-style chat, planning a secret event). CD9 is a warning to the other participants in the conversation that they should not write anything they wouldn't want adults to see.

Although most commonly used by children and teenagers, CD9 can also be used by adults who are chatting online during work time, as a warning that a colleague or supervisor is present. CD9 may also be used by unfaithful lovers or spouses as a warning that their partner is present, or by anyone wishing to keep a conversation secret (e.g., when planning a surprise party).

CD9 is often just written as 9 "Parent Watching". Other codes with similar meanings include:

Image for CD9

When I write CD9, I mean this: meaning of CD9 CD9 means "Watch out! Adult about!"

Summary of Key Points

"Code 9 (Adult Alert)" is the most common definition for CD9 on Snapchat, WhatsApp, Facebook, Twitter, Instagram, and TikTok.
Definition:Code 9 (Adult Alert)
Type:Cyber Term
4: Difficult to guess
Typical Users:
Adults, Teenagers, and Under 13s


Examples of CD9 in Sentences

Here are examples of CD9 being used in conversations:
  • Maria: What time did you get home last night?
  • Anita: CD9. How's your brother?
  • Ted: Dude, you were so drunk on Saturday! Do you remember what you said to Cindy?
  • Mark: CD9. Do you have a copy of the assignment that Mrs. Laws gave us?

An Academic Look at CD9

CD9 is classified as a cyber term as opposed to an initialism abbreviation or an acronym. Initially, cyber term terms were introduced for brevity but, particularly with the advent of predictive texting and on-screen keyboards, they are now mostly employed for fun. Cyber terms differ from icons because they are not pictorial representations.

What Did We Say before Texting and Social Media?

Before the digital era, we might have whispered something like "I can't talk now" and changed the subject, instead of using CD9 to mean "Code 9 (Adult Alert)". 

Example of CD9 Used in a Text


Help Us To Improve Cyber Definitions

  • Do you disagree with something on this page?
  • Did you spot a typo?
  • Do you know a slang term that we've missed?
Please tell us using this form.