look up any word, like leh:
 
1.
Intense; hardcore.
"Things are gettin' serious up in here."

"I made some serious cash last night."
by **** you March 18, 2003
128 35
 
2.
Slang word used in the north of london
meaning some thing good.

or

some one that does not find what they do important.
Them creps are serious cuzz.

or

"Your not serious"-JME of meridian crew
by Voltige K-I-D June 10, 2004
141 90
 
3.
Grave in quality or manner, or being of such importance as to cause anxiety.
- like making sure that your space shuttle is safe to use to re-enter a your own planet's atmosphere... THAT is serious.
by Anonymous February 01, 2003
57 32
 
4.
1. something generally good or fun

2. something gangsta or crime related which is impressive

immortalised by garage emcee JME, "it's serious, serious". and so on.
1. "oi this new Mos Def song i got is serious"

2. ye i heard about that boy that pars around E8 but he's a pussy, he aint serious"
by Lord Sinista October 28, 2005
34 25
 
5.
Used to differentiate between the two most common reasons for visiting the loo. Allows for open discussion of bathroom activities in public or in mixed company.

n. a bowel movement

v. to defecate
Bill: I need to go to the bathroom before we leave.
Tina: Is it serious?
Bill: Yes!
Tina: Then we'll never get out of here!

-or-

Bill: I know you're still putting on your makeup in here but I gotta go serious!

-or

Bill (with newspaper tucked under arm): I'll be back in 20 minutes, I have to conduct some serious research.
by Clubshub January 26, 2010
8 8
 
6.
looking nice....as in someone/something that would interest you.
Wow! Shorty is looking serious in those jeans.
by Adrianne March 24, 2004
25 25
 
7.
serious is a beast pker and skiller, he rocks the world so hard, like omg look this elite up!
omg dude i saw serious today and he killed all world 26. he is sooo good!
by [IR]Serious March 12, 2009
6 13