head of state

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun 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.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the chief public representative of a country who may also be the head of government