Definition from Nolo’s Plain-English Law Dictionary

1) An act, document, product, or anything else sanctioned or authorized by a public officer or public agency. Examples might include an Official Boy Scout knife or emblem, or an official warranty, membership card, or set of rules. 2) A public officer or government employee who is empowered to exercise judgment. 3) An officer of a corporation or business.

Definition provided by Nolo’s Plain-English Law Dictionary.