Which word refers to someone who is disabled by illness or injury?

The term "invalid" historically refers to someone who is unable to care for themselves or manage their daily activities due to an illness or injury, particularly in a context where their condition significantly hinders their capacity to function in society. It conveys the idea of someone being rendered helpless or disabled due to physical or mental limitations.

In this context, the word is often associated with a state that is perceived as a lack of validity or capacity, which arises from a condition that affects one’s abilities fundamentally. While other words like "incapacitated," "handicapped," and "impaired" can describe similar situations, "invalid" specifically emphasizes a more permanent condition, often linked to long-term health issues. The usage of "invalid" in healthcare and legal contexts further underlines its connotation of being recognized as unable to fulfill roles due to a disability.