A piece of information lacking in the other definitions is the fact that priapism, while sounding like fun, is extremely painful and requires surgery (
aka draining the blood out) to fix. Priapism can be caused by several things, including the bite of certain venomous creatures on or near the genitalia, overdosing on a "male enhancement" supplement, spinal cord or
brain injuries, clots, or sickle-cell anemia. Note that if you have been able to fap or bone your gf/
wife/
prostitute for four hours plus, you do not have priapism. If not treated properly, priapism can result in loss of genitals or possibly life.
Guy:
Dude, I think I took to much Viagra. My dick feels like it's gonna blow!
Dude: That's priapism. It's not good, guy. You need to go to the hospital!