Niner-niner 

When you say something so stupid, that your friends question your mental stability.

“People in Denmark speak Denmarkese right?”

“Oh my god, you’re a fucking niner-niner”

Niner-niner by yungjonasty November 11, 2020

on the niner 

act of standing against a wall to cause the effect of invisibility.

Hey wheres billy. oh there he is, he must have been on the niner.

on the niner by Jarrin Dennis February 16, 2004

Forty niner 

A woman who is a 4 but thinks she is a 9

Hey bro, look at this tinder thot forty niner requiring men be 6 feet tall, 6 figure income, looking like a model, and they are broke, far and aren’t even cute.

Forty niner by MGTOW September 10, 2019

Ground Point Niner

In aviation, "ground" control is always "121" in the first three digits of the frequency. In this case, Ground point niner would be "121.900".

Boston Tower: American 1070, cross runway four left and four right via Charlie, then contact ground point niner on the other side.

Ground Point Niner by BostonTower July 8, 2007

minor niner 

A term used by students in grades ten and up to describe grade nines, especially those that are new to the school.
Generally identifiable by the large packs they hang around in, the lost, confused and sometimes excited or amazed look on their faces and the constant asking of directions to their classes.
See freshman

Grade Nine Student *Lost look on face*: Wheres Rm 154?
Grade Eleven Student*Looks Annoyed*: Down the hall and to the left
Grade Nine Student * Smiles *: Thanks!
Grade Eleven Student *Rolls Eyes* Whatever.
*Turns to Friends* Minor Niners
*Friends Nod in Agreement*

minor niner by k e l l bell* September 4, 2006

niner cap

A large stool, with curvature.

Dude, I just totally dropped a niner cap. It looked like a brown boomerang in the toilet bowl.

niner cap by Lazynugz April 3, 2011

Rusty Niner

A variation of the sixty-nine, except both participants are eating out the others balloon knot.

My girlfriend and I tried a Rusty Niner, but I didnt like the way her ass tasted.

Rusty Niner by Buzzzzzzz July 31, 2006