CFR > Title 32 - National Defense > SUBTITLE A—Department of Defense > CHAPTER I—OFFICE OF THE SECRETARY OF DEFENSE (parts 1 to 399) > SUBCHAPTER C—DoD GRANT AND AGREEMENT REGULATIONS (Parts 21–37) > PART 21—DoD GRANTS AND AGREEMENTS—GENERAL MATTERS > SUBPART F—Definitions (§21.605 to §21.680) > 21.635—Contracting officer.