The porn video tag "teen-anal-solo" can be broken down into three parts:
1. Teen: This refers to the participants in the scene, who are typically younger adults or individuals in their late teens.
2. Anal: This signifies that the primary focus of the scene is anal sex, which involves penetration of the anus.
3. Solo: The term "solo" implies that there is only one participant in the scene, meaning it does not include any other partners or performers.
So, this tag means a solo scene featuring a teen engaging in anal play or sex without the presence of another person.