undefeated

/ˌʌn.dɪˈfiː.t̬ɪd/

形容词

（在体育比赛中）保持不败的，未尝败绩的
The team managed to remain undefeated in the final weeks of the season.
在本赛季最后几周的比赛中，这支球队成功保持不败。