It’s the name of a modern jazz standard. The version I was just listening to was Coltrane and Monk from the “Live at the Five Spot 1958” album. Turns out, the Five Spot was an old jazz club at 5 East 5th Street on Cooper Square (or, as someone rather hysterically put it, in “the bohemian section of Greenwich Village in New York City”), that later moved a few blocks away.
Anyhow, back to Epistrophy. What does it mean? I haven’t the slightest idea, but Thelonious Monk knew. Ask him.