Here is what happens when you google democracy: "a system of government by the whole population or all the eligible members of a state, typically through elected representatives."
https://www.merriam-webster.com/dictionary/democracy: 1a: government by the people especially : rule of the majority b: a government in which the supreme power is vested in the people and exercised by them directly or indirectly through a system of representation usually involving periodically held free elections
dictionary.com: government by the people; a form of government in which the supreme power is vested in the people and exercised directly by them or by their elected agents under a free electoral system. a state having such a form of government: The United States and Canada are democracies.
You said the US is not a democracy, all definitions I can find says it is.