The story
First used in the lyrics of the Steve Miller Band's 1972 song "Enter Maurice" ("whisper sweet words of epismetology in your ear and speak to you of the pompatus of love.") and popularized in their 1973 song "The Joker" ("Cause I speak of the pompatus of love"), but having no apparent meaning in either song. The lyric was inspired by the lyric "Oh my darling, let me whisper sweet words of pizmotality and discuss the puppetutes of love" in The Medallions' "The Letter" written by Vernon Green; puppetutes, from puppet, described a fantasy paper-doll or puppet-like girl.
Etymology from Wiktionary, CC BY-SA 4.0.