Florence Nightingale, often referred to as the 'Lady with the Lamp, ' was a pioneering NURSE who is credited with revolutionizing the field of nursing during the 19th century. She is best known for her work during the Crimean War, where she and a team of nurses improved the unsanitary conditions at a British base hospital, drastically reducing the death count. Her work in nursing earned her the title of 'NURSE' (5 letters).