From Longman Dictionary of Contemporary Englisha necessary evila necessary evilMUSTsomething bad or unpleasant that you have to accept in order to achieve what you want Mr Hurst regarded work as a necessary evil. → necessary
Examples from the Corpus
a necessary evil• I, for one, consider yard work to be a necessary evil.• Mr Waldegrave's shambolic performance in the press conference was a necessary evil.• We do not look at government as a necessary evil.• It may be a necessary evil, but it is surely an evil.• However, the authors, like most others then and now, saw those shortcomings as a necessary evil in maintaining control.• They're a necessary evil, like the woman who sawed off all my lovely hair.• Lawyers are a necessary evil that I try to use as little as possible due to their cost.• Bureaucracy was also a necessary evil to cope with the ravages of war.• They viewed such methods as a necessary evil, unavoidable yet somehow beneath their dignity. 