A futile waste of time and energy.
"I tried to reason with her, but I was pissing against the wind"
Passing gas while navigating thru a crowd in bar/nightclub. Derived from drive-by.
"The club was way too busy last night. Left early, but did a viscious fart-by on the way out."
A definition added to urban dictionary under the influence of alchohol/drugs which seems to the contributor to be witty, but on sober reflection is worthless.
"Made a pissed entry on Urban Dictionary last night, Let's hope the editors were pissed too!"