“合法性”的反义词：非法性。...

他们打算在法庭上对他的要求的合法性提出质疑。They intended to challenge the legality of his claim in the courts.反托拉斯当局需要通过调查该协定的影响和目的来确认其合法性.Antitrust authorities must investigate the effect and purpose of an agreement to determine its legalit...

“合法性”的英语可以翻译为：[经] legality，validity ...