a name/label used in reference to someone you should have been allowed to call grandmother, BUT because your parent is an AB/DL you are forced to refer to her as a MommyAnn; emphasis on the word mommy. In doing so against your will animosity, hostility, and ill will develop leading to the creation of your term of endearment, GrandCunt.
(1).Some people have a grandmother, others have a grandma, I was forced into having a MommyAnn until the day I revolted, now I have a GrandCunt.
(2).Bootz, "Shoo Fresh you know you rich grandma buy you those dank kicks you need fo school..."
Fresh, "Jigga please! you know I aint got no grandma, I got stuck with a GrandCunt.