gain ground

If an idea or belief gains ground, it becomes more popular or accepted.

如果一个想法或信仰gain ground，意思其实就是这些东西变得更加受欢迎或被接受了。

To become popular, to make progress, to advance.

变得更受欢迎;取得进展;得到肯定

这个表达其实来自于军队，它暗指军事战斗是一方从另一方夺取领土(ground)这样一个行为，夺得领土就算是取得了进展。相应的，失去领土也就是lose ground作为这个习语的反义词，意思是遭受挫折，不能继续之前的进步。

As Airbnb gains ground in many cities all over the world, many people complain that they can no longer find a place to live. Landlords would rather rent their places out to tourists and earn more money.

随着Airbnb在全球许多城市的发展壮大/普及，许多人抱怨说他们再也找不到住的地方了。因为房东宁愿把房子租给游客以便赚更多的钱。