thickens , thickening , thickened
When you thicken a liquid or when it thickens, it becomes stiffer and more solid.
Thicken the broth with the mashed potato.
加点土豆泥使汤变浓。
If something thickens, it becomes more closely grouped together or more solid than it was before.
The dust behind us grew closer and thickened into a cloud.
我们身后的尘土越来越密,变成了浓密的一团。