nacronym - A name that started as a bunch of letters but now it's just

A name that started as a bunch of letters but now it's just a name and people cuss at it because it doesn't make sense anymore.

My teacher is called "FROG" but it stands for "Freaking Ridiculous Old Guy." Now he yells at us for no reason.

My mom's business is called "FLIP" but it used to be "Fancy Ladies In Pretty Clothes." Now it's just a burger place and she yells at me.

My dog is called "POOP" but it used to be "Puppies Of Outstanding Personality." Now he just poops on the floor and looks at me like I'm an idiot.