What does the term 'anhydrous' refer to?

The term 'anhydrous' specifically refers to a substance that contains no water. In various chemical contexts, the prefix "an-" indicates absence, and "hydrous" relates to water. Therefore, when something is described as anhydrous, it signifies that it has been deprived of water, making it an essential term in fields such as chemistry, where water can significantly affect the properties and reactions of different substances.

In contrast, the options that suggest the presence of water, acid, or sugar do not align with the definition of anhydrous. By clearly identifying the absence of water, one can understand how it applies to different substances, such as in the case of anhydrous salts or dehydrated compounds, which are often critical in various scientific applications.