departing, or about to depart
As soon as he finished his meal he was off like a prom dress.
by The Return of Light Joker September 03, 2011
Similar to "gotta jet" or "gotta bounce", this phrase means to leave somewhere very quickly with speed matching that of prom dress removal at a post-prom party.
Talk to ya later, I'm off like a prom dress.
by jonlindg October 04, 2005