A person who derives sexual gratification from observing the naked bodies or sexual acts of others, especially from a secret vantage point, A person who derives sexual pleasure from secretly observing other people, especially when such people are engaged in some sexual activity, a viewer who enjoys seeing the sex acts or sex organs of others

Describing a voyeuristic image of the view up a woman's skirt, noun_ An image of this kind, verb_ transitive To take a voyeuristic picture up the skirt of (a woman), especially surreptitiously