For the purpose of this subchapter—

(1) “agency” means—

(A) an Executive agency;

(B) a military department; and

(C) an employing authority in the legislative branch;

(2) “employee” means an employee in or under an agency;

(3) “international organization” means a public international organization or international-organization preparatory commission in which the Government of the United States participates;

(4) “transfer” means the change of position by an employee from an agency to an international organization; and

(5) “reemployment” means—

(A) the reemployment of an employee under section 3582(b) of this title; or

(B) the reemployment of a Congressional employee within 90 days from his separation from an international organization;

following a term of employment not extending beyond the period named by the head of the agency at the time of consent to transfer or, in the absence of a named period, not extending beyond the first 5 consecutive years, or any extension thereof, after entering the employ of the international organization.