a varitaion on the game of tag, in which the player who is "it" tags another, and while doing so, shouts out the name of a known STD, such as "the clap." The person who is now "it" now has to tag another player, and shout the name of another STD. If an STD is repeated, that player is eliminated.
The following is an example of a game if STD Tag:
Johnny: *Tags Jenny* Herpes!
Jenny: Damn, now I'm it...*runs after Billy and tags him* Gonorrhea!