And that comes from a really famous poem in English taken from The Canterbury Tales, and it's the first part of The Canterbury Tales called the general prologue.
We have Geoffrey Chaucer to thank for the earliest known instance of the word with this meaning; in " The Merchant's Tale" (from The Canterbury Tales), he named one of the characters " Placebo."
Works like Hyperion are firmly grounded in that tradition, borrowing structure from Canterbury Tales and the Decameron, even taking its name from a Keats poem.
Do some research into Chaucer's use of irony in The Canterbury Tales and discuss how he makes ironic portraiture of the pilgrims, especially the Prioress 4.