The word "grats" or gratz is a truncated form of the word congratulations, or congratz. The word is used by people in online games (mainly mmorpg’s and mostly it is seen in PristonTale) its use is to congratulate someone on accomplishing something. I.e. moving up a level.
(Gold level up! appears above Jacl3's head)
Jacl3: w00t level 34!
l337357: grats man
by Jacl3 October 3, 2004
Pronounced "Grash"
Based off of Shakespeare's character Gratiano from Merchant of Venice

noun - one who chatters idly at length without making sense, someone who says something pointless or asks a stupid question

adjective - something pointless, monotonous, doesnt make sense
noun - He is a grat because everything that comes out of his mouth is crap and I can never understand him.

adjective - This class is grat because all we do is listen to stupid lecture and take notes
by The Anti Grat November 2, 2006
Basically just another word for great. But the word grat is grat -er.
Girl: You look great!
Other Girl: Well you look grat!
by nathan wong January 8, 2015
Did you hear the new backstreet boys song?
Dude, it's grat!
by hthang April 25, 2008
When something is lame, stupid or sucks its grat.
"You hear that new song on the radio?"

Yea, that shit was grat!
by Drep859 January 10, 2011
Slang for gratuitous, or free - having similarity to meaning as in a giveaway. An exclusive special in preview or experience - similar in context to perk.
The download comes grat with a preorder of the album.
by charvelguy June 17, 2010
tobbaco, cigarettes used so teachers cannot find out if a pupil smokes
"You got any grat!?"
by skinz May 25, 2005