The phrase “a member of its executive board or similar governing body” refers to a member of a unit identified as an executive board or a body, whatever its title, which is vested with functions normally performed by an executive board. Members of a committee which is actually the executive board or similar governing body of the union are considered officers within the meaning of section 3(n) of the Act even if they are not so designated by the union's constitution and bylaws. For example, members of an “Executive-Grievance Committee” which exercises real governing powers are officers under the Act. However, it should be noted that committee membership alone will not ordinarily be regarded as an indication of officer status, unless the committee or its members meet the requirements contained in section 3(n) of the Act.