A number which was eaten by 7

n. The birth name of somebody who has changed their name. Most commonly attributed to trans people, but can be attributed to any person who has changed their name. (sometimes written as two words: dead name)

v. 1. To call somebody by their deadname.
v. 2. To out somebody's deadname to the public.

A firearm chambered in 9mm. Properly used, it refers to the 9x19mm cartridge, aslo known as 9mm Parabelum or 9mm Luger. Though several other calibers are 9mm in diameter, they should not correctly be refered to as "nines".
9x17 AKA 9K AKA 9mm Kurtz AKA 9mm short is properly refered to in ghetto slang as a .380, referring to .380ACP the proper American nomenclature.
9x18 AKA 9mm Makarov is not commonly found in North America, and is therefore unavailable to most criminals.
9x21, is a more powerful variation of the 9x19 cartridge, and the two are not compatible in autopistols.
9x23, is a powerful cartridge, but is seldom found in cheap pistols, and therefore out of reach for most criminals.

When you're on IM or texting and a parent or other bothersome person is breathing down your neck, type "9" and the person who you are talking to will understand and switch to a different, more boring topic, like school or work.

9mm pistol carried by a fellow emc-er

Different than a 9mm in a few ways.

-9s are fired sideways, rarely hitting anything. Used by street gangs.
-9mms are fired properly and hit where they are fired most of the time. Used by human beings.

a pistol with a caliber of 9mm