What do you call it?

Some people can call an object by a name that is not actually it's name and it's really cute. For instance, I love when Eadie has something stuck in her teeth and she asks me if I can get the "gentle floss" and get it out. Or how our family has affectionately named an involuntary spasm of the diaphragm a "wiccup" because that's what the kids think they're called. But it's annoying when someone calls it a "tramboline" instead of a "trampoline". Especially when that someone once mocked another older person who called a place to watch movies a "cinnamon" instead of a "cinema". I guess maybe some things stop being cute with age. (Actually a lot of things probably do but we don't want to go there. YUCK!)