The chief public representative of a country who may also be the head of government WordNet 3.0 & Open English WordNet

A head of state is the public persona who officially embodies a state in its unity and legitimacy. Wikipedia

The most senior public representative of a state Wikipedia Disambiguation

Term used in politics, law, and diplomacy. Wikipedia Disambiguation

Official who holds the highest-ranked executive position in a sovereign state Wikidata

The chief public representative of a nation having duties, privileges and responsibilities varying greatly depending on the constitutional rules; a monarch in a monarchy, and often styled president in a republic, but variations such as collegiality exist. Wiktionary

The chief public representative of a nation. Wiktionary (translation)