adj.未受到挑战的;不成问题的;未引起争论的;无异议的;
例句:
She couldn't let that pass unchallenged.
她不能让它无异议地通过。
For decades this practice went unchallenged.
这个做法数十年来均未遭遇挑战.
From 1914 to 1924 he was supreme and unchallenged.
从1914年到1942年.他是首屈一指,无可匹敌的.