Master Lock 

A sexual position where the woman lies on top of the man and puts her ankles behind her head. The man wraps his arms in front of the woman's legs and then behind the woman's head, giving the man total control. This position is used almost exclusively for anal sex.

I had Sally in a Master Lock last night, it was awesome!

Master Lock by Djsyndrom325 October 18, 2008

Master Key Shitty Lock 

A man is the master key ie his penis the woman is the lock ie her vagina.

Jan: Why is a man sleeping around is ok while a woman doing the same thing is a slut?

Bill: Master Key Shitty Lock.

Jan: what does that mean?

Bill: A Master Key Penis can open many Different locks, a Shitty Lock Vagina will open with many different keys

Jan: That's sexist.

Bill: No it is the truth.

Master Key Shitty Lock by McOwnage August 14, 2016

Masterlock 

Poorly made shit for shit lock. There are several ways to unlock it without picks. It's possible and extremely easy to make a shim out of a soda can and unlock it.

Jack thought his bike was secure with his Masterlock, but the next day someone guessed his combination in 3 minutes and rode off into the sunset.

Masterlock by A man in a suit October 10, 2005

Masterlocked 

A way of attacking someone in prison. You get hold of a padlock via paying off guards of stealing one of a gate and put it in your sock. Get 8 other people to do this and then beat the victim to death with them.

Did you hear? Dave got masterlocked!

Masterlocked by udking420 June 28, 2020

Masterblock 

This is the act of cock blocking yourself. This can be done for a variety of reasons including, but not limited to; fidelity requirements, embarrassment, awkwardness, sobering up in the nick of time, etc. Doesn't happen very often and typically results in feelings of confusion and possibly guilt.

The hottest chick ever hit on me last night at the bar, but with my wife home with the kids and no one else to save me, I masterblocked by donning a helmet and a hula hoop, while running out the door screaming like a little girl.

Masterblock by 00Snort00 October 18, 2011

Mastercock 

The mammoth cock that always seems to show up when on the website chatroulette.com

oh man i gotta find me som titties on chatroulette.com. OH SHIT! MASTERCOCK! PRESS F9 PRESS F9!!!

Mastercock by roosterstroke March 7, 2010

Masterlackivation 

The lack of motivation experienced after jerking off.

Zach was suppose to write a paper until masterlackivation set in.

Masterlackivation by the_wood December 26, 2009