The phrase “to add insult to injury” means: To heap scorn upon one already injured.
Apperson, in English Proverbs and Proverbial Phrases (1929), reports that this familiar expression first appeared in Latin, iniuriae qui addideris contumeliam, “injury which is added to insult”, in the fifth book of the fables written by the Roman writer of the first century, A.D., Phaedris.
But we probably owe our acquaintance with it from its use by Dickens in Pickwick Papers: ‘ To offer me a sandwich, when I am looking for a supper, is to add insult to injury.”
