back·light 
(băklīt′)
(băklīt′)n.
1. A type of spotlight, used in photography, that illuminates a subject from behind.
2. A light that amplifies the brightness of an LCD screen by illuminating it from behind.
tr.v. back·light·ed or back·lit (-lĭt′), back·light·ing, back·lights
To light from behind: The photographer backlit the subject for a dramatic effect.