A nickname for
gonorrhea, an STD.
Origins:
The clap got its nickname from the methods of treating
gonorrhea on the war front. This painful way of treatment
involved two soldiers holding their comrade's arms, two soldiers holding their comrade's legs, and one soldier "clapping" his hands on the comrade's penis, discharging the fluid.
"Did you hear what Steve caught from me?"
"Yeah,
the clap."
"No... I had herpes. He has
the clap!?"
"Yeah... hey, now you have
the clap, too!"