A cultural theory that escaped from 1970s academia, postmodernism went mainstream in the '80s.
It became widely (and often vaguely) used as a label for art, music, film, and more.
Merriam-Webster defines postmodern this way: "relating to ... any of various movements in reaction to modernism that are typically characterized by a return to traditional materials and forms (as in architecture) or by ironic self-reference and absurdity (as in literature)."
As the Los Angeles Times observed, "In fashion, as in food, the new adjective describing the new look is Post-Modern. Even a hair salon boasted in a recent advertisement in LA Style that it specialized in 'Post-Modern' hairdos." Nikki Finke, Sept. 12, 1988
Photo: garryknight from Flickr