What is "promposal"

n. (context informal English) An invitation, especially one which is made in an elaborate manner, in which the invitee is asked to accompany the inviter to a prom.

"Promposal" is the twentieth episode of the seventh season and the 164th episode overall of the American sitcom Modern Family. It aired on May 4, 2016 on American Broadcasting Company (ABC). The episode is directed by Ken Whittingham and written by Stephen Lloyd.