Meanings
Derived from the fables of Phaedrus in the first century C.E.. The story was of a bald man who swats at a fly which has just landed on his head, but instead hits himself on the head. The fly comments, "You wished to kill me for a touch. What will you do to yourself since you have added insult to injury?" The actual wording appears in English from the middle of the 18th century. This etymology is incomplete. You can help Wiktionary by elaborating on the origins of this term.
How to pronounce "add insult to injury":
To further a loss with mockery or indignity; to worsen an already unfavourable situation.
Example: "As if the hostile takeover weren't enough, to add insult to injury they scrapped ninety percent of our products and replaced them with their own."