Monodimple 

It's a single dimple on someone's face, usually on the cheek.

Tom Fletcher's famous dimple on his left cheek is a monodimple

Monodimple by Chibi88 October 6, 2008

mononipple 

a mononipple is when someone only has one nipple

mary’s nipple piercing got caught on her shirt, now she has a mononipple.

mononipple by patitiddies January 13, 2022