A social norm or custom that is so outdated or unnecessary its ridiculous and usually creates more problems than it ever solved, but also one that certain factions of society seem to want to hold on to for nostalgic purposes.
Jenny: I wonder why we never saw Laura Bush while idiot was president?
Joe: Because those down home Texas bastards think their women should be seen and not heard.
Jenny: Well that's pretty retrofucktastic.
-Verb: To become fucked by a decision that created temporarily favorable elements, having later realized an unfavorable counterpart to the decision.
-Noun (i.e., to be in retrofuck): A state that results from a decision wherein temporarily favorable elements are created for its decider, and where the decider is later, however, totally fucked by the same decision.
Tom is retrofucked because he borrowed his mom's car to take Kelly to the drive-in - now he's grounded, and cockblocked.
He is in retrofuck because he cheated on his history exam, but was later ratted on and, as a result, failed.
The act of using Facebook to locate old classmates, friends and coworkers who you wish you would have fucked in the past, and fucking them.
Darrin used Facebook to locate Aimee, a girl he used to have a crush on in high school but never hooked up with, in the hopes that he would be able to retrofuck her.