Trans-oral is a term used in the context of adult content to describe a specific type of sexual activity. In this case, "trans" refers to across or beyond and "oral" refers to oral sex. So, trans-oral indicates that an object or body part (usually a penis) is being inserted into someone's mouth and then passed across the throat into the esophagus or stomach area for further stimulation. This practice can be considered extremely risky due to potential choking hazards and internal injuries. It should only be performed with extreme caution, if at all.