The term "sub" is loosely associated with the BDSM community and refers to a person who occupies a submissive role during an erotic or dominant-submissive relationship. A sub is an individual who voluntarily accepts a lower or inferior position to his partner who occupies a dominant role. A submissive individual may show obedience, devotion, and surrender to their dominant partner.
Sub (bdsm role): The Sexiom Handbook
Definition and designation of the term Sub (bdsm role) from the Sexiom Handbook. Quick and briefly.