Sovereignty is freedom. It means you have no rulers. It means making your own decisions, and being responsible for their consequences. Having complete control over your actions. Not being a slave.
It’s not generally a word applied to individuals. Most of us have rulers. Most of us don’t make our own decisions. Most of us are slaves. When people use the word, they’re generally referring to sovereign states. Countries that completely control a territory, with ultimate authority over their subjects. Or popular sovereignty, the principle that “Governments derive their just powers from the consent of the governed”.
Individual sovereignty is rare. Most of us consent to government. Most of us accept our chains, even grow to love them. I’m doing my best to change that, too.