Sentence:  Then came a maid with hand-bag and shawls, and after her a tall young lady. She stood for a moment holding her skirt above the grimy steps,..., and the <WSD>light</WSD> of the reflector fell full upon her. 
Meaning of the word marked with <WSD> tags:  Visible electromagnetic radiation. The human eye can typically detect radiation (light) in the wavelength range of about 400 to 750 nanometers. Nearby shorter and longer wavelength ranges, although not visible, are commonly called ultraviolet and infrared light.