Years ago, I came across a word that referred to the process of using a formal name (like a brand name) in place of or interchangeably with the actual term. For example, Jell-o instead of gelatin or Kleenex instead of tissue.

Having worked for Scott Paper company, we were especially sensitive to the latter.

--Jay

On Branding

Q: Is there a term describing words such as cellophane and thermos
that were formerly trademarks but now have a generic meaning?

A: The process of a word going from brand to generic is called
generification; and the legal term for this process is genericide. It is an
apt term because despite the sentiment that 'imitation is the highest
form of compliment,' if a trademark becomes generic, a company's
branding power is lost — which is the reason that Xerox, Kleenex, Dixie
cup are not generics; their parent companies fight this trend fiercely.

I think that is the word I was looking for.

Thanks,
Jay