Definition - What does Boi mean?
Boi is a colloquial term for either a submissive biological female who dresses and behaves in a masculine or butch manner, or an effeminate man. The first sense of the term is most commonly used in lesbian D/S relationships, but not exclusively in this context.
A boi may be male or female, transsexual, transgender, or intersex. A person typically adopts the term as they struggle to identify with more mainstream gender labels. No matter what the person’s gender or sexual orientation, a boi tends to be young and boyish or adolescent in appearance.
The term boi was originally coined in the black LGBTQ community, but its use has now spread throughout mainstream society.
Kinkly explains Boi
A boi is typically the younger person in a gay or lesbian relationship, or one who prefers relationships with older people. In this definition, boi does not denote any particular age, but rather, an age that is relative to that of their older partner. Because of this, people may identify as bois long after their 20s, so long as they continue to date much older individuals.
As a relatively younger person, a boi may take a more casual or carefree attitude towards sexual relationships or commitments. The boi will typically take on a more submissive role than their more experienced, dominant partner.
Due to their submissive tendencies, some young straight people in BDSM relationships may also prefer to identify as bois.