Section 553.102 - Definitions(a)Agency, as used in this part, means an executive agency as defined in 5 U.S.C. 105 .(b)Annuitant, as used in this part, refers to a current or former civilian employee who is receiving, or meets the legal requirements and is applying or has announced intention to apply for, an annuity under subchapter III of chapter 83 or chapter 84 of title 5, United States Code, based on his or her service.(c) Retiree, as used in this part refers to an annuitant as defined in paragraph (b) of this section.56 FR 6206, Feb. 14, 1991, as amended at 65 FR 19644 , Apr. 12, 2000