Friend Common Amjad Mutual Means Grammar Literally Bit

(“Mutual friend” literally means a friend who you are a friend of. A bit of a redundancy, isn’t it? Do you have a friend who doesn’t consider you a friend of his/hers?

“Common friend” means a friend who is shared by two or more people. I’m sure you and your friend have some common friends.

Unfortunately, due largely to the undereducation of Americans, who now happen to be the de facto custodians of the English language, bad grammar and semantics spread like wildfire, eventually becoming “correct”.) - Source, a comment on Quora (https://qr.ae/pNzMD8)