Is there a term for when one word is used as a generic blanket term, even though it may be technically inaccurate?

Periodically I'll hear people refer to their six-cylinder engine as a V6, when it's actually an inline-six or a horizontally opposed engine. And I've actually done this myself--unintentionally called an engine a V6 that I knew as actually an inline-six.

I'm reminded of generic trademarks, but in this scenario there is no trademark.

I can't think of any other examples at the moment, but I would describe the phenomena I notice as using one term that means a very specific scenario, to be a blanket to refer to all related scenarios.

Solution 1:

Misnomer: a wrong name or inappropriate designation

From MW Definition

Your example is similar to calling a tissue a "Kleenex" where one is describing a generic noun using a popular brand name. Apparently that's also called a Proprietary Eponym. Source