Step 13 

In 12-step fellowships, such as AA, 'step 13' is an informal way of refering to having sexual relationships with someone of the group

Joe: I just did Step 13 with Mary
Mike: Wait, I thought it was twelve steps?
Joe: I don't think you realize what the 13th step is...

Step 13 by Phoenix732 March 12, 2017

13th step 

Any person in a 12 step whom sexually prays on people in the program who have under 1 year of clean time.

Damn Dani 13th stepped the fuck out Chris!
Now Chris questioning his identity in the rooms.
Chris now has to find new meetings and new friends, and new rides to meetings.

13th step by Madman800 January 17, 2019

13th step 

the 13th step is used to describe the efforts of an old timer who tries to screw a newcomer or someone with less than a year of sobriety.

jim had 10 years of sobriety and attended AA regularly. when he laid eyes on sophia, the newcomer, he decided to 13th step her.

13th step by rich v. March 27, 2007

13th Step 

For people who've really gone to 12 step meetings it's commonly known that the Thirteenth Step (really 13th step) is getting laid.

13th Steppin' is looking to get laid.

It can also inply that a 12-stepper is a Ho.

He out 13th Steppin' tonight.
She's 13th Steppin' him.
He's a 13th Stepper'.
Stay away from him. He's a 13th stepper.

13th Step by Phukk October 28, 2006

13th step 

A metaphor used to describe someone who is close to suicide, fallin off the wagon, or about to relapse

At a gallow there are aproximately 12 stair steps to the hangmans noose, the 13th step is the hanging.

Also known as the stairway to heaven

Example1
Person#1 John's not here today, guess he finally took the 13th step.

Person#2 When's the funeral?
Example 2
Person#1
This class makes me wanna take the 13th step
Person#2
Oh are you in AA?
Person#1

I hate you

13th step by InvitroCannibal February 20, 2015