What term refers to a solid, liquid, or contained gaseous material that is no longer useful?

The term that accurately describes a solid, liquid, or contained gaseous material that is no longer useful is "Waste." Waste encompasses all sorts of materials that, after their useful life, need to be managed through disposal or recycling processes. This includes everyday items discarded from home, industrial byproducts, and material generated from various sectors that are no longer needed or suitable for use.

"Hazardous waste" specifically refers to waste that poses substantial or potential threats to public health or the environment due to its quantity, concentration, or physical, chemical, or infectious characteristics. While hazardous waste is indeed a type of waste, it does not encapsulate all forms of waste—only those that have harmful attributes.

"Byproduct" is a term used to describe a secondary product that is produced in addition to the principal product, and usually still has some potential use or value. It does not necessarily mean the material is no longer useful.

"Disposal material" is not a standard term used in waste management contexts. Instead, it refers to waste that is set for disposal but lacks precision in the description of the waste type itself.

Thus, the correct term that broadly defines any solid, liquid, or gaseous material that is no longer useful is "Waste."