“慢慢传开”可以翻译为“spread gradually” 或 “gradually become known” 。
例如：
The news slowly spread gradually throughout the village.（这个消息在村子里慢慢传开了。）
The story gradually became known to more and more people.（这个故事慢慢被越来越多的人知晓，也就是慢慢传开了 。）