It is often used to describe substances that have had all of their water removed, such as:

* Anhydrous salt: A salt that has been dehydrated, leaving only the salt crystals.

* Anhydrous ethanol: Ethanol that has been dried to remove all water.

* Anhydrous ammonia: Ammonia that has been dehydrated to remove all water.

The term "anhydrous" is also used to describe substances that do not contain water molecules in their structure. For example, anhydrous calcium chloride is a common desiccant, meaning it absorbs water from the surrounding environment.

Here are some examples of how "anhydrous" is used in a sentence:

* "Anhydrous calcium chloride is used to dry laboratory equipment."

* "The reaction was carried out in anhydrous conditions."

* "The anhydrous form of the drug is more stable than the hydrated form."