"Person" or "company", herein used interchangeably, means any individual, receiver, administrator, executor, assignee, trustee in bankruptcy, trust, estate, firm, copartnership, joint venture, club, company, joint stock company, business trust, municipal corporation, political subdivision of the state of Washington, corporation, limited liability company, association, society, or any group of individuals acting as a unit, whether mutual, cooperative, fraternal, nonprofit, or otherwise and the United States or any instrumentality thereof.