DECA dance
A dance which takes place most commonly at a DECA state, regional or national conference. The girl to guy ratio is usually something like 3:1 at a state competition, and most of the guys are ugly unless you go to a good conference. They are mostly awesome dances, and at the (inter)national conferences the attendance is in the thousands. Afterwards, many sexual encounters, toga parties and elevator parties may occur, and secret stashes of alcohol snuck into the conference are busted out.
At the PA state conference last year, a drunk kid showed up to the DECA dance in nothing but boxers, and couldn't believe they wouldn't let him in! I say fuck the dress code!