"You canker blossom!" 3 Shakespearean Insults
early 16c., altered by folk etymology from curry favel (c.1400) from Old French correier fauvel "to be false, hypocritical," literally "to curry the chestnut horse," which in medieval French allegories was a symbol of cunning and deceit. See curry (v.). Old French fauvel is from a Germanic source and ultimately related to fallow (adj.); the sense here is entangled with that of similar-sounding Old French favele "lying, deception," from Latin fabella, diminutive of fabula (see fable (n.)).
the spice, 1680s, from Tamil kari "sauce, relish for rice."
“Currying favor” with someone means trying to ingratiate oneself by fawning over that person: “The ambassador curried favor with the dictator by praising his construction projects.”