Wiktionary
ac72
n. (context lang=en sports) a catamaran sailing racing yacht, with a wingsail mainsol, developed for the http://en.wikipedia.org/wiki/en:2013%20America's%20Cup
Wikipedia
AC72
The AC72 (America's Cup 72 class) is a wing sail catamaran box rule, governing the construction and operation of the yachts to be used in the 2013 Louis Vuitton Cup selection series and the 2013 America's Cup.