Lesion/ˈliːʒn/ Definition 1 of 2Pro Tip 1/3Medical Specificity Refers to a specific area so it's used with precision in medical contexts. The MRI revealed a lesion in the cerebral cortex. Pro Tip 2/3Severity Varies 'Lesion' doesn't specify severity; it can range from minor to serious. Despite the lesion being benign, follow-up is necessary. Pro Tip 3/3Not Always Visible Some lesions are internal and not visible without medical imaging. Her headache was caused by a lesion that only a CT scan could detect.