A female (or the occasional male) R&B singer who sings the hook (exclusively) on a rap "song."
"Who is your favorite hook bitch? Mine is Ashanti."
Note: Neyo and Akon are also hook bitches.
The person that sings the chorus of a rap song; Can be male or female.
Similarly, the verb "hook" can be derogatory when applied to hook bitches, implying that a hook bitch is sleeping with the rapper or rappers she or he is singing with, possibly to advance her or his own career.
Ashanti, John Legend, and Alicia Keys are okay, but my all time favorite hook bitch is Mary J. Blige.
Ashanti only got with Nelly because she hooked for him.
I hear Rihanna's hooking on the new Jay-Z song.