The term "solo-trap" in the context of a porn video refers to a scene where a person pleasures themselves, specifically engaging in autoeroticism or masturbation. In this scenario, there is no partner involved and the focus is on the individual's solo experience. The word 'solo' indicates that it's one person involved, and 'trap' often refers to something that captures attention or arouses interest. So, a "solo-trap" tagged video would typically feature an individual engaging in self-pleasuring activities, possibly involving various toys or objects to heighten their experience.
Remember that this term is for adult audiences who are familiar with pornographic content, and is not suitable for those under 18 years of age or anyone who might be offended by such content.