"Oosht" is an exclamation, mostly used in the negative sense, to describe something that's gone bad, failed, or not happened in the right way. It could also be used to exclaim when one is "done for". It's the more Kannada version of the Indian "gone case".
Exam aa? Oosht only. Going to fail.
The rice is oosht da. Don't eat it.
My dad caught me smoking. I'm oosht only now.
Added 2013-04-12 by Thairsaadam