What does “Bongwater” mean?
The water that goes into a bong or water pipe that makes it function. After extended use the water usually becomes murky. Some mischievous stoners will claim it contains THC because of this and will try to trick newbies into drinking it, but don't bother--it's just gross water that needs to be dumped.
Example usage for Bongwater
“This bongwater is looking a little dingy. Should we replace it?”