The state or condition of being useful; usefulness.
User Defined Definitions
"a company that performs a public service; subject to government regulation"
"the quality of being of practical use"
"a facility composed of one or more pieces of equipment connected to or part of a structure and designed to provide a service such as heat or electricity or water or sewage disposal"
"used of beef; usable but inferior"
"capable of substituting in any of several positions on a team"