RSA – Rear Seat Accessory – A member of the opposite gender, usually decorative in nature, that occupies the passenger’s portion of a motorcycle seat.

R.S.A. is an abbreviation for Rancid Skunk Ass, May be hard to fit into the average sentence, but RSA is the extreme of disgusting.

Richard's - Saving - Awesomeness

a not well documented phenomenon which has been observed on the island of Jamaica. RSA is known to reduce damages by hurricanes which is seen from evidence from hurricanes Ivan, Dennis, Emily and most recently Gustav