[Tn, Tn.pr, Dn.t] ~ sb (to sth) invite sb to do sth (esp to take part in a contest or to prove or justify sth) 要求某人做某事（尤指参加竞赛或证明某事正当）: challenge sb to a duel, a game of tennis 要求某人参加决斗﹑ 网球赛 * She challenged the newspaper to prove its story. 她要求这家报纸证实报道的真实性. 
[Tn] order (sb) to stop and say who he is 命令（某人）停步并说出是谁; 问口令: The sentry challenged the stranger at the gates. 哨兵查问在门口的陌生人. 
[Tn] question the truth, rightness or validity of (sth); dispute 怀疑（某事）的真实性﹑正确性或有效性; 提出异议: challenge sb's authority/right to do sth 怀疑某人是否有权力[权利]做某事 * challenge a claim, an assertion, a verdict 对某要求﹑ 主张﹑ 判决质疑 * This new discovery challenges traditional beliefs. 这项新的发现对传统观念提出了异议. 
[Tn] test the ability of (sb); stimulate 考验（某人）的能力; 激励; 鞭策: The job doesn't really challenge him. 这项工作不能真正考验 他. 
[Tn] make a formal objection to (esp a member of a jury) 宣布反对（尤指陪审团某成员）.> challenger n person who challenges, esp in sport 提出竞争要求的人（尤指体育运动中）; 挑战者.
challenging adj offering problems that test sb's ability; stimulating （为考验某人的能力）提出难题的; 激励的; 挑战的: a challenging job, test, assignment, etc 激励人的工作﹑ 考验﹑ 任务等.