the act of blowing one's nose without a kleenex. this is typically done one nostril at a time by using the thumb to pinch off one nostril while blowing hard to clear out the opposite nostril. the procedure is then reversed to complete the act.
this is known, ironically, as the "farmer's kleenex" because farmers typically don't carry tissues with them in the field, so they just use this "tissue-less" method instead.
dude, i really have to blow my nose...do you have any tissues on you?
no man...looks like you'll have to use the farmer's kleenex!