What describes a condition of having a dry mouth?

Having a dry mouth is medically referred to as xerostomia, which is characterized by the condition of the oral mucosa becoming dry due to a lack of saliva. This condition is often identified by dry mucous membranes, particularly in the oral cavity. Dry mucous membranes occur as a direct result of decreased salivary secretion, leading to discomfort and potential complications such as difficulty swallowing, speaking, or maintaining oral health.

The other conditions mentioned do not directly describe a dry mouth. Poor dentition refers to the state of one's teeth and their health rather than the moisture level in the mouth. Pericoronitis involves inflammation of the tissue surrounding a partially erupted tooth, usually a wisdom tooth, which is more about dental infection and pain than dryness. Dental caries, or tooth decay, is a result of tooth damage caused by bacteria and does not inherently relate to the moisture level of the mouth.

Therefore, identifying dry mucous membranes is the most accurate way to describe the condition of having a dry mouth.