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
When two or people talk about pointless things and never anything important or "deep".
1) When a group of people talk thoroughly about surreal scenarios that wouldn't ever happen, but the way they talk make it seem plausible and important, like Zombie Survival Plans and What To Do When The Dinosaurs Come Back
2) Jack: So, yes, as we walk up this hill why don't I tell about the different types of clouds?
Jill: Oh you and your Nonversations!