Thought this might be fun. Can you name a word that you have only ever heard once in your life in a song? It should be a word that has a definite meaning, no 'sha la la' etc. I'll start with 'porcomorph'. From the song Yodelling Yippie by Ed Sanders. "Mayor Daley that porcomorph, he chopped down his yodelling friends". A reference to the 1968 Chicago riots. Porcomorph meaning he resembles a pig of course. Let's hear some more. Then maybe someone could write a song using all of them together!
You have to include "pompatus" here. Steve Miller used it in two songs but I don't think I've heard anywhere else.
Paraselene "Paraselene woman, I'm your man on the moon, And like a grain of diamond dust, you float, and my devotion's outer crust cracks" Also a contender for "have you ever had to pause a song to google what the words mean?"
It may be in an album cut by one or more other artists, but I believe Aretha Franklin's "Think" is the only Top 40 hit to have the word "psychiatrist" in its lyrics.
Budgie used the word Quacktor in the song "Quacktors and Bureaucrats". I can't recall its use anywhere else.
Frank Sinatra - At Last Long Love (lyrics by Cole Porter) Never heard "Turtle Soup" in a song before, but it's legendary in this tune