The word "retainer" used in rap vernacular often is referring to keeping a thug on hand that is willing to do dirt. The celebrity retains this person's services thru cash payment, or other bartering options such as
weed or
pussy in the event that a punch needs to be thrown (or otherwise) and the celebrity would be open to a potential costly lawsuit, whereas the retainer does not have enough
money worth be sued for, etc.
When Charlemagne Tha God was instigating
Nelly during an interview, he was warned "Hey,man...just say what you wanna say. We'
re all
men. I keep retainers just for guys like you".