UXO

Unexploded ordnance (UXO) means military munitions that:
(1) Have been primed, fuzed, armed, or otherwise prepared for action;
(2) Have been fired, dropped, launched, projected, or placed in such a manner as to constitute a hazard to operations, installations, personnel, or material; and
(3) Remain unexploded, whether by malfunction, design, or any other cause. (10 U.S.C. 101(e)(5))

Source

32 CFR § 179.3

Scoping language

This part includes definitions for many terms that clarify its scope and applicability. Many of the terms relevant to this part are already defined, either in 10 U.S.C. 101, 10 U.S.C. 2710, or the Code of Federal Regulations. Where this is the case, the statutory and regulatory definitions are repeated here strictly for ease of reference. Citations to the U.S. Code or the Code of Federal Regulations are provided with the definition, as applicable. Unless used elsewhere in the U.S. Code or the Code of Federal Regulations, these terms are defined only for purposes of this part.