eighteenth base

Sticking your middle toe in the tip of a guy's penis while playing with his balls with your other foot

Chad: Hey, Jakob, I heard you got pretty far last night!
Jakob: Yeah me and Sadie got to eighteenth base last night! It was fucking magical

by Baddyfuckdaddy February 1, 2017

april eighteenth

On April eighteenth every girlfriend or wife has to give it up. Similar to Valentine's day.

by HarryCaStle June 7, 2016

When you become a legal adult and you can make your own decisions but your parents or any one older than you thinks you are still a child.

"It's her eighteenth birthday so she's going to get a tattoo."
"She thinks she's so grown because its her eighteenth birthday."

The age at which a girl is just old enough to have sex with an older man without him becoming a registered sex offender.

"Hey, its my eighteenth birthday! Now I can hook up with DILFS!"

by dilflover67 September 19, 2025

When one wants to stay sober for a given period of time

nah man, im eighteenth amendmenting for the night

by Posterboy69 April 21, 2010