To completely fuck up something despite having taken every safety precaution except for not killing your damn self for being such an idiot.
OMFG, you just mased your $100k car in that accident!
by opsman February 21, 2003
Mased is similar to based. Except the term mased is used to describe something you see but it depends on what it is.
Example 1:

P1:Awww look at those two people hugging. It's adorable:)
P2: Yeah that's pretty mased man.

Example 2:
P1: Oh my god, can you believe what Becky just did? What a bitch!
P2: Yeah that's pretty mased if you ask me

Example 3:

P1: I hate my school. My teachers. My classmates. They can't understand me!!! Y'know what will teach them?! My dads AK.
P2: Don't do it man, it isn't worth it.
P1: But...yeah. You're right. It would be mased of me to do that.
by thepicklegod July 1, 2021
When you put a motherboard in a case without standoffs, and then turn it on and wonder why the whole damn thing catches on fire, you have officially mased your motherboard.
by Kuja February 25, 2003
“Yo, no funny shit, i finna mase ya niggas.”

“His lil ass betta pull up. or he finna get mased”.
by D-Maul August 8, 2018
" Mase us a cheeky till friday bro?"
by motyma November 23, 2011
A rapper who is: "Young, black, and famous, with money hangin out the anus."
"Young, black, and famous, with money hangin out the anus." Mase - Can't Nobody Hold me Down
by HA HA MIKE JONES HA HA February 11, 2009
A Rapper, the Harlem World nigga, after second album became a minister
Mase was the shit
by Me May 26, 2003