The porn video tag "brunette-fuck" consists of two parts:
1. "Brunette": This refers to the hair color of one or both participants in the scene, which is brown. In this context, it specifically points out that the female participant(s) has a brunette (brown) hair color.
2. "Fuck": This term is used as a verb to describe various sexual activities such as penetrative sex, often involving vaginal or anal intercourse. It also implies a strong and passionate sexual encounter.
So, the tag "brunette-fuck" means a porn video featuring a brunette female participant(s) engaged in intense and passionate penetrative sex.