What does state of domiciled mean?

The correct term is state of domicile. There is also a Certificate of Domicile by State. Domicile simply means a permanent legal residence. A person can have multiple temporary residences but only one domicile. An example is a person who lives in New York most of the year: it's the place where he is registered to vote, where he receives mail, and where he renews his vehicle registration and license. Perhaps he also has a temporary or vacation residence in Florida or South Carolina. New York is his state of domicile or his domiciliary state. Florida or South Carolina is the state of his temporary residence.