1. The inability to recognize certain sensory stimuli: "Because of an extensive neural damage as the result of the car accident, his friend experienced aural agnosia."
2. Loss of the ability to recognize people or objects and their meanings: "A tragic consequence of the industrial accident was the onset of agnosia making it impossible for the some of the workers to continue working because they couldn't remember how to perform their jobs anymore."
3. In medicine, losses of comprehensions at the levels of central nervous systems of any of the senses: "The sensory spheres of the agnosias may be intact, but such patients are unable to assimilate the meanings of whatever the senses indicate."