: free from water and especially water of crystallization.

Why does anhydrous mean?

Anhydrous literally means "no water." In chemistry, substances without water are labeled anhydrous. The term is most often applied to crystalline substances after the water of crystallization is removed. Anhydrous can also refer to the gaseous form of some concentrated solutions or pure compounds.

What does anhydrous mean chemistry?

Definition. An anhydrous material does not contain any water (H₂O) molecules.