A person who derives sexual pleasure from secretly observing other people, especially when such people are engaged in some sexual activity. / An obsessive observer of sensational or sordid subjects.

The derivation of sexual satisfaction by watching people secretly, especially when those being watched are undressed or engaging in sexual activity.

plural of voyeur

plural of voyeurism

spy or voyeur

voyeuristic

Of, relating to, or derived from voyeurism or a voyeur.

plural of voyeurist

In a voyeuristic way.