0 something unpleasant that must be accepted in order to achieve a particular result:
The invisible part of politics - lobbying, majority maneuvers, and persuasion - is a necessary evil to manage problems effectively.
On a libertarian account, the state is ultimately seen as a necessary evil and should remain extremely limited in power and scope.
The former saw the jobber as a necessary evil, the latter saw the jobber as an exploitative agent.
While authors may see peer review as a necessary evil, most recognize that it plays an important role in validating their work.
Coercion is thus considered a necessary evil for the good of society and eventually for the long-term interests of every member.
It is surely more of a necessary evil.
Surely in a case of that kind of boys of eighteen and nineteen an ordinary short term of imprisonment is a necessary evil.
The punishment of the criminal is a necessary evil, an evil which we all deplore, and which we would all see avoided if possible.