This porn video tag, "trans-big-cock-girl," can be broken down into three parts:
1. Trans: This refers to the gender identity of the performer, specifically a transgender individual. In this context, it usually means that the performer was assigned male at birth but identifies and presents as a woman.
2. Big cock: This aspect of the tag describes the size of the performer's genitalia. In the case of a male-to-female transgender individual, "big cock" implies a larger than average penis for someone with male anatomy.
3. Girl: This term refers to the gender presentation or identity of the performer, in this case, a woman.
So, this porn video tag is describing a transgender woman (assigned male at birth) with a large penis who is engaging in sexual activity, likely with another partner. The focus of this tag is on the transgender aspect and the presence of a big cock as part of the performer's anatomy.