形容词不倦的，持续的，不松懈的

1. 不屈不挠的：unfixed 解脱的 | unflagging 不屈不挠的 | unflaggingly 不衰地

2. 不减弱的,不垂头丧气的：Pretence 借口,假装,自吹 | Unflagging 不减弱的,不垂头丧气的 | Delegate 委员,代表

3. 不松弛的：unfixedunset 不固定的 | unflagging 不松弛的 | unflappability 不慌张

4. 不衰的：agonizing 烦恼,苦闷的 | unflagging 不衰的 | pressing 紧迫,切实的

1. 七彩网.英语单词

1. （支持、努力、热情等）不懈的，持续的
    If you describe something such as support, effort, or enthusiasm as unflagging, you mean that it does not stop or get less as time passes.

    e.g. He was sustained by the unflagging support of his family...
           他得到了家人不断的支持。
    e.g. ...unflagging optimism...
           不变的乐观

adj

1. unceasing

    e.g. unfailing loyalty
           unfailing good spirits
           unflagging courtesy

    Synonym: unfailing

2. showing sustained enthusiastic action with unflagging vitality

    e.g. an indefatigable advocate of equal rights
           a tireless worker
           unflagging pursuit of excellence

    Synonym: indefatigabletirelessunwearying