16s 

Bay heads will find this term in the song "16's Wit Me" by Ya Boy. It refers to 16 bars (or a set of two lines) in a rap battle.

"Who wanna go 16s wit me?"

16s by Stampede July 30, 2004

two 16s 

Someone's ability to look fly and talk the talk

Riley: John's two 16s are on par with his confidence.
Ashley: Never seen him look so sexy before.

two 16s by SidePizza December 2, 2019

UCMJ says 16's OK 

A phrase used for a military person who wants to have relations with a person who could possibly be under age but the UCMJ says as long as she's 16 its fair game.

Also can be used to combat the phrase 16 will get you 20

#1

Sailor: Hey check out that girl over there she is fine as hell i would destroy her pussy

Marine: Dude she looks 16 years old

Sailor: Hey UCMJ says 16's OK

#2

Guy 1: 16 will get you 20

Guy 2: Yea but UCMJ says 16's OK

UCMJ says 16's OK by Mr. Tiddlesworth June 6, 2010