ex officio

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adverb & adjective By virtue of office or position.

from The Century Dictionary.

• noun By virtue of office (and without other especial authority): as, a justice of the peace may ex officio take sureties of the peace: also used adjectively: as, an ex officio member of a body.

from the GNU version of the Collaborative International Dictionary of English.

• From office; by virtue, or as a consequence, of an office; officially.

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

• adjective By virtue of the office that originated it, or of the title held

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

• adjective by virtue of an office or position
• adverb by virtue of position