Which term describes a state of being diseased or unwell?

The term that best describes a state of being diseased or unwell is "sickness." This reflects a broader understanding of health that encompasses not just physical ailments but also the overall experience of feeling unwell. Sickness typically indicates an individual’s subjective experience of symptoms and discomfort, which may or may not be linked to a specific diagnosis.

The other terms, while related, do not specifically capture the subjective experience associated with being unwell. "Health" denotes a state of physical and mental well-being rather than a state of being diseased. "Disorder" refers to a disruption in normal bodily functions or mental processes but is more clinical and less about the patient's perspective. "Condition" can describe a state of health (such as a chronic illness) but is often used in a more general sense to indicate the status of a particular issue without necessarily implying the experience of illness. Thus, "sickness" is the most fitting term for describing a state of being diseased or unwell.