意思：知难而退是指在面对困难或挑战时，能够明智地放弃继续努力，避免无谓的浪费时间和精力。这种态度表现出一种明智和谨慎的心态，能够避免不必要的损失。

怎么读（音标）：zhī nán ér tuì [ʈʂɨ ˥ nan ˧ er ˥ tʰuei]

用法：知难而退常用于形容人在面对困难时采取的一种态度或行为。它可以作为动词短语使用，也可以作为形容词短语使用。

例句1：当他自己无法完成老师布置的任务时，他选择了知难而退。

When he found himself unable to complete the task assigned by his teacher, he chose to give up.

例句2：有时候，知难而退比坚持下去更明智。

Sometimes, it is wiser to give up than to persist in the face of difficulties.

例句3：她并非因为胆怯而选择知难而退，而是因为她认识到自己没有足够的能力来应对这个挑战。

She didn't choose to give up because she was afraid, but because she realized that she didn't have enough abilities to face this challenge.

例句4：在面对困难时，知难而退并不意味着软弱，它可以是一种明智的选择。

Giving up in the face of difficulties does not mean weakness, it can be a wise choice.

例句5：有时候，我们需要知难而退，放弃一些东西，才能获得更好的机会。

Sometimes, we need to give up and let go of something in order to have better opportunities.

同义词及用法：放弃、撤退、退缩、认输

编辑总结：知难而退是一种明智和谨慎的态度，在面对困难或挑战时，能够明智地放弃继续努力。它强调了个人应该根据自身情况和能力来判断何时该放弃。与其坚持不懈地做无用功，不如及时认清现实并采取正确的态度。