Sei

To be incredibly epic at basically everything. Seems to be from a different dimension, though this is up for debate. Will not admit to having ninja skills even though said skills are witnessed regularly. Prone to anime-type reactions (aka loud and obvious), usually ending in some form of destruction.

Person 1: WTF happened in here!? All the desks and chairs are destroyed!!
Person 2: Someone pissed off (insert random name here).
Person: What an idiot, everyone knows (insert random name again) is a Sei.

by Kiri :D June 21, 2010

Sei

Sei is pure and untainted, yet knowledgeable in the vast world of sexual deviancy. He needs to be likened to a donut when talked to. He needs to be talked to gently and sweetly, otherwise he will become rigid with fear. He needs to feel validated with gentle words of encouragement. He would appreciate sprinkles on top of him. He is a endless bottom and a brat, that will relentlessly tease you unknowingly because he's too innocent to know any better.

"Sei looked up with eyes glazed over, just like the donut that he is, confused and scared of the sexual advances of women who found him too cute to be true and couldn't resist googling over him." "Look at this lil soft harmless Sei!" "That Sei just wants to sit on your lap and be petted until he falls asleep."

by IsItSo February 05, 2022

Sei

Sei can be used as a term for smart, funny, and helpful person but mainly used for referring to a very good friend. Commonly used on discord while talking on servers or in dm's. It can also mean when someones a Sei that theyre hobby is engineering, they are an engineer or was previously.

-Poz, aka tall_fellow/Sundrop was here

"Your such a Sei!"

by tall_fellow aka Poz January 25, 2022

Sei

Every bad quality you can name.

Hawk is posting pictures that are depressing, and won’t y’all about it. He is being a sei.

by Randomposter333 March 15, 2018

sei sei

a magical creature in a school in romania

sei sei is the best creature

by oof_fan December 08, 2022

the Seis

n. an affectionate nickname for Ratty Room 6 in Brown University's Sharpe Refectory, where the brothers of Alpha Epsilon Pi eat dinner together every Wednesday at 6 pm

Jon: "Alright, I gotta run to the lab now, need to finish a Western blot."
Dave: "Are you coming by later for a little uh...a little...Ratty action at the Seis?"
Jon: "Definitely, I'll see you there."

by Railsplitter April 28, 2007

Seis

A person who breaks the Sixth Commandment which signifies the person slept with a married person.

"Oh shit! He just pulled a Seis"

High five for scoring with a married chick man!

by Seis716 July 20, 2010