Mansteris 

A guy you mess around with when you hang out with him for no apparent reasion. You do this even though you know better, it happens almost everytime you hang out. This is how someone becomes a Mansteris. These can be good things or bad things. Mansteris(s) can become very negitive people in your life and an object your friends will use to make fun of. You and your mansteris(s) activities usually take place in random places when you don't think your friends are looking.

(1)Hey Rebecca, there goes your mansteris, boR.
(2)Omg! she made out with her mansteris in the woods at his party!?

Mansteris by [Letsgo4awalk] September 30, 2006

Mastering Physics

Literally cancer. Homework website used by colleges to make students google every question on chegg or yahoo answers because clicking anything will take of 50%. Giving college students cancer since 1998.

Person 1:Did you do Mastering Physics yet?

Person 2:Yeah it gave me cancer.

Mastering Physics by AweStrucK July 24, 2015

Mastering Chemistry 

A website created to make the lives of American college students a nightmare through the use of nazi-like grading on significant figures and rounding throughout 15+ pages of hell. Commonly referred to as a bitch for changing 1 number in each person's given values to piss people off.

"Hey have you done the Mastering Chemistry for this week yet?"

"No but I heard it's a real killer."

"Yeah I tried the hints and couldn't even work through those!"

Mastering Chemistry by CHE108 May 15, 2012

Mastering Engineering 

An online homework program designed to rob college students of their hard-earned money and serve as a crutch for professors too lazy to write their own homework assignments or to teach. Its purpose, beyond making millions for the publishing company, is apparently to reduce the number of engineering graduates in the United States by utterly demoralizing and destroying their confidence in an effort to force them to drop the program and/or kill themselves.

I used up all but one attempt on this stupid Mastering Engineering problem, before I realized it had switched everything to kiloOhms instead of Ohms! And then I still got it wrong! FML!

Mastering Engineering by kypok April 16, 2012

Mastering the gift 

Female masturbation

Her room mate unexpectedly walked in while she was furiously mastering the gift!

Mastering the gift by GAM Brian September 9, 2016

mansterooni 

A person who slaps their thighs together

Some sluts are Mansteroonis

mansterooni by Frankane April 13, 2015

james marsters 

The guy who plays "spike" in Buffy The Vampire Slayer.

girl 1: what's with spike's white hair?
girl 2: james marsters is hott,don't cuss his hair.

james marsters by Nastaran January 19, 2006