Voyeuristical is an adjective that refers to someone who engages in voyeurism, which is the practice of observing people who are engaging in intimate activities without their knowledge or consent. Some synonyms for this word include prying, nosy, intrusive, and snoopish. Other similar words to consider include eavesdropping, peeking, spying, and lurking. These terms all describe actions that involve observing others without their permission and can have negative connotations. It's important to respect other people's privacy and boundaries, so it's best to avoid engaging in voyeurism or similar activities altogether. Instead, try to develop healthy and respectful relationships with others.