to be a sign that something important, and often good, is starting to happen, or to make something publicly known, especially by celebrating or praising it

The president's speech heralds a new era in foreign policy. 总统的演说预示着一个外交政策新时代的开始。

This drug has been heralded as a major breakthrough in the fight against breast cancer. 据称这种药是在对抗乳腺癌方面取得的一个重大突破。

a sign that something will happen, change, etc.

If this first opera of the season is a herald (= sign) of what is to come, we can expect great things. 如果本季的这第一部歌剧是一个信号，那么我们可以期待接下来的剧目会非常精彩。

in the past, a person who carried important messages and made announcements