B1
If something freezes or is frozen, it becomes hard and solid because it is very cold.
Dictionary examples:
The pizza froze solid before the delivery guy reached my house. (0.0)
My tongue froze to the lamppost. I shouldn't have licked it! (0.0)
The chocolate bar froze so hard, I thought it was wood! (0.0)
When the lake freezes (over), we can go skating on it. (28.3)
The ground had frozen hard/solid. (32.4)
Water freezes at a temperature of 0°C. (53.0)