flush it

flush it  {v. phr.},  {slang}
1. To fail (something).
I really flushed it in my math course.
2.  {interj.},  {used imperatively}
Expression registering refusal to believe something considered stupid or false.
"You expect me to buy that story? Flush it!"
Categories: {interj.} {slang} {used imperatively} {v. phr.}