utility has 8 distinct synonyms spread across 5 of its 8 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. Its one recorded opposite is inutility.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
a company that performs a public service; subject to government regulation
the service (electric power or water or transportation) provided by a public utility
“the cost of utilities never decreases”
(economics) a measure that is to be maximized in any situation involving choice
(computer science) a program designed for general support of the processes of a computer
“a computer system provides utility programs to perform the tasks needed by most users”
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
“the price of the house included all utilities”
used of beef; usable but inferior
capable of substituting in any of several positions on a team
“a utility infielder”
Synonyms, antonyms and the broader and narrower relations for utility come from Princeton University’s WordNet. Full sources and licences.