Trademark infringement (what I'm guessing you're asking about) only applies to other companies operating in the same space. There's no reason someone can't name

Trademark infringement (what I'm guessing you're asking about) only applies to other companies operating in the same space. There's no reason someone can't name their product after a common noun. Or even name their company the same thing as another company, but operate in another space (e.g. Despite the existence of Apple Computers, I could open Apple Dry Cleaners). Or am I misinterpreting your question?