jack in 

1. to connect to a system via wire or ethernet

2. to log in to a website or computer

When I try to jack-in I get an error.

jack in by DrZin July 13, 2003

jack in 

v.
1. To gain entry; to connect, as to a network.
2. To enter or connect by deceptive or unscrupulous means, esp. with malicious intent.

"He tried to jack in and take down their group from the inside after he heard what they were saying about him behind his back."

jack in by tlc November 20, 2004

jack in 

1. v. The opposite of masterbating; wordjack off/word
2. n. An uptight cock-sucker; wordfuck-face/word

I enjoy a good game of jacking in.

That billy is such a jack in

jack in by jim jimson November 27, 2002

Jack in the boxing 

To masterbate at work in a cubical or perimeter guard kiosk.

The officer was caught jack in the boxing in his guard kiosk.

Jack in the boxing by Got caught January 16, 2014

jack in the jocks 

1. To masturbate discreetly in your pants while they are still on.

2. To masturbate whilst being aroused by a hamburger.

3. To have a boner in your underwear (jocks).

1.I was feeling especially horny in the office today so I did a quick jack in the jocks and moved on with my day.

2. This burger is making me hungry for a jack in the jocks.

3. I woke up with a raging jack in the jocks this morning.

jack in the jocks by Sup_Ladies October 24, 2014

jack in the crack 

Jack in the Box

Im going to Jack in the crack for a burger, want one?

jack in the crack by P-Feezy October 3, 2003

Jack in the Back 

1. Basically, a kid posing as a bamf who stands behind his/her crew and is afraid to take real action in a fight.
2. Someone who claims they can kick ass, and they chicken out when someone wants to go.

James: I saw Jason behind those punks fighting after-school today. What a whimp.
Rob: I know, such a jack in the back.

Jack in the Back by baddefinintionperson May 28, 2009