Do blini have to be thin?

This seems to be more of a linguistic question to me. It depends on who you ask. In the region where I live: not necessarily, both the American style and French crêpe style pancakes are sometimes called "блин" and "блинчики" (little pancakes).

But for a lot of people it's only the French thin ones. And they call the other one "оладушки". (Read: oladushki) It's not exactly defined by region as much as simply what you're used to.

Also: the word is also a curse word, although a very childish one. The English version might be 'crap', I think.