Wiktionary
lesser of two evils
n. (context idiomatic English) The more desirable of two bad alternatives.
Usage examples of "lesser of two evils".
The people accepted me as the lesser of two evils, when they thought he was dead.
It is true that his move to draw his sword against me was not indicative of a friendly disposition towards me, but at least, if there were any choice, he seemed the lesser of two evils.
It had been the lesser of two evils, and he disliked having been put in that position.
Davis, on the principle that the lesser of two evils was to be preferred, hoped that Ivar would win.
Vaughn struggled to reassure himself that he had chosen the lesser of two evils.
The poor girl was forced to choose between the lesser of two evils.