Precoined words

I hope this word doesn't already exist, because I want to invent it. I want a word for the situation that exists when you go to make up a new word for something, and there's an obvious combination or construction, but that word already has a more specific meaning, so you can't use it.

Here's an example. Say that for some reason, modifying or decorating the roofs of cars became popular, and specialists started to offer their services for modding your car. Calling such a person a "cartopper" would make sense, if we didn't already have an object with that name.

Or there's the reality show type where someone shows their survival skills out in the wilderness. Such a person could be called a survivalist, if that term didn't already have other connotations.

So we could at least console ourselves by saying that the good term had been precoined, right?

Yeah, I know. It doesn't make me feel any better either. I'm gonna go get my car made into a convertible at the cartoppers' while I sulk about it.