acuity [ ah-ku´ĭ-te] 1. Acuteness (see acute [def. 2]); the level of severity of an illness.

[Fr. fr. L. acuere, to sharpen] 1. Clearness, sharpness of a sensory function, e.g., visual acuity. 2. In emergency and critical care medicine, the severity of a hospitalized patient's illness and the level of attention or service he or she will need from professional staff.

Patient acuity refers to the severity of an illness or medical condition. It is often used to designate which clients should be seen first.

Patient acuity is a measurement of the level of care a patient need based on the severity of either an illness or mental condition. Patient acuity can also determine the staffing level required to treat patients when used in the hospital setting.

Acuity does refer to a form of sensitivity, but it is most often applied to the perceptual senses (as in “visual acuity” or “auditory acuity”). It is also frequently used in reference to the intellect (as in “mental acuity”).