Thank you for that context, even if it mostly relates to your personal experience and back story. I agree that we should be careful how we use words, but I don't think you can easily argue that "democracy" has become meaningless out of context, while also imposing your own idiosyncratic context to claim that the US isn't a democracy.

As to your question, I would say that the U.S. constitution defines (indeed, guarantees) the country as having "a republican form of government" (at the state level, but this is maintained at the federal level), and that the processes and principles that it puts in place, such as representative elections, qualify that system as democratic.