Base 2.5 

It refers to a point in the base system between 2nd base and 3rd base. It is dry-humping. It has always seemed more than simple groping but it is less than the handjobs/blowjobs of 3rd base. Dry-humping now has a definite place on the base system.

guy1: hey, y'know the base system?
guy2: yeah?
guy1: wher does dry-humping go?
guy2: base 2.5
guy1: ok cool thats good to know
guy3: you guys are fucking retarded

Base 2.5 by uberjai July 27, 2012

Base 2.5 

Base 2.5 uses powers of 2.5 for the numbers, it is considered binary and Base 5 at the same time.

Oh look! Base 2.5 isn't used! What a bad day!

Base 2.5 by MandullorTheBEEKER October 31, 2021

25th base 

25th base is the act of having sex with 2 women, at the same time, while playing Starcraft on the PC against 7 people and owning them all. While blindfolded. This also makes you more godly then Chuck Norris, Bruce Lee, and Arnie combined. You also win at life. Any base after this is for pure show and tell, since if this feat is accomplished, you are God.

Jack: I got to 25th base last night. Twice.
Everyone within 50 meters: ALL HAIL THE NEW GOD!

25th base by DecadeOfAggression January 4, 2009

25th base 

Sneaking into the bear enclosure at the zoo and penetrating different orifices on each bear in the order: 1. Anus 2. Ear 3. Nose 4. Mouth. There is no 5.

"I went to 25th base at London Zoo last night and they couldn't sew it back on!"

25th base by Aliquail November 14, 2007