"State" vs "country" as "nation"

The NOAD reports the following definitions for those words.

• state: a nation or territory considered as an organized political community under one government
• nation: a large aggregate of people united by common descent, history, culture, or language, inhabiting a particular country or territory
• country: a nation with its own government, occupying a particular territory

The difference between nation and country is that country refers to the people, the territory, and the government, while nation refers to the people, and the territory. In the case of federal countries (e.g., USA, Austalia, Germany) a state is just a part of the country; in the other countries (e.g., Italy, France), the state coexists with the country.

There is no standard definition. State can mean sub-national or national, or wider in the case of the Plurinational State of Bolivia; in the United Kingdom it is often taken to mean all levels of government considered together. For example, the United Kingdom currently regards itself as made up of four countries (for example here) in one nation, which is not how other places see themselves. It is all a matter of local use, usually driven by political and historical reasons.

There are other oddities: the Commonwealth of Nations has the Commonwealth of Dominica and the Commonwealth of Australia as members; Australia is a federation made up of states and territories. Meanwhile the United States includes four commonwealths as if they were states and holds two more as unincorporated territories.