look up any word, like usuratonkachi:
 
1.
When you go to the bathroom to take a shit and instead of it being enjoyable. it feels like the world is ending if only the smell dosent take you first.

It may often splash up, as a final "fuck you" which makes the wiping process that much worse.
X:Dude I dont know what i ate last night but I just dropped a koser and am still surprised im here.

Y: Yeah man, those really can ruin not only a day but a week.
by Gern-haha December 13, 2010

Words related to Koser

death dump rank shit splash monkey stink turd bomb
 
2.
for something to be nasty, not right or just something you wouldnt do
oh my goodness did you see her nappy hair, i swear that aint koser
by chanae November 22, 2003
 
3.
A big peice of shit, also known as "Mike", or "uni", or "Koala Bear". All mean the same thing. An asshole.
Your as dumb as a koser!
by DeadzeroCustom August 18, 2003