stealth masterbating 

When one wacks off as quietly as possible so as to not disturb the people in the same room.

Sam: I hope no one notices I am stealth masterbating
Girl friend: Sam ... are you wacking off!!!!
Sam: Oh Shit!

stealth masterbating by themanwiththeplan9192 April 4, 2010

master bung blaster 

Sensei of all ass pounding, fudge-packing, stromboli boys. Known to lurk in the shadows of elementary bathrooms awaiting tender bungs. A.K.A. Walter "Marvin".

Hey Timmy, I wouldn't go in there. MB squared is on the prowl.

master bung blaster by The Old Man (Slurth) April 21, 2005

masterblast 

masterblast means to masterbate

i masterblast pretty much every night!

masterblast by monnie_o February 25, 2009

Master Funnery Sausage 

E-9 in the Marine Corps.
A Master Gunnery Sergeant who has been in so long that he no longer cares. Often refers to himself as 'Master Funz' to confuse boot ass POGs that he calls on the phone.

Master Funnery Sausage Smith didn't feel like working today so he prank called every shop in the unit.

Master Funnery Sausage by MLCpl August 6, 2010

Master Douche 

A jerk who has mastered the art of being an asshole

The CBS executive who fired Charlie Sheen is a Master Douche. Master Douche's are NOT winners!

Master Douche by Makiavelli March 30, 2011

Master Chief 

The most amazing soldier in all of history. As a Spartan II, he was trained to be the best soldier ever. He has saved thousands of galaxies and planets, and is definitely better than Spartacus, pie, the muffin man, and cute puppies. Do not anger his epicness.

Master Chief: Hey ladies, I just got back from saving the universe.

Ladies: OMFG!!!!! SIGN OUR BODIES IN PERMANENT MARKER!!!!!!!!

Master Chief by The God of Halo 4 December 27, 2012

Oodee Master 

n. A person who contributes enough definitions to the Urban Dictionary to rank in the "Top-10 Most Frequent Contributors" list.

Please Santa, I wannabe an Oodee Master.

Oodee Master by D'emon March 20, 2003