A man or woman who provides a valuable service to the opposite sex. In the case of the male Playa (from my own experience) there are many duties and responsibilities a Playa has in uplifting and empowering woman to a status where dependence upon any man is unnecessary. Playas MUST be able to listen genuinely, sincerely fill the roles of Homie-Lover-Friend, be good at providing sexual satisfaction, and hold an internal balance between emotion and purpose. If a Playa has good enough game he would be able to fill his life with strong, independent women who are not seeking a relationship (and often buy gifts for their "Homie-Lover-Friend").
It shouldn't be used in a sentence. While it can be a known fact that a Playa is what they are, it is not necessary and even egotistical to lay claim to such a title. Playas often find other terms to redefine their "Game".