An RV is also a term for a
re-entry vehicle. This refers to any vehicle designed to survive the fall into
Earth's
atmosphere from space and the corresponding deceleration and heat produced by
air friction on a object moving at
orbital or high
ballistic velocity.
Early spacecraft had RVs for their crews; the 'command capsule' that the Apollo missions returned were RVs. The Space Shuttle is technically an RV; however, the use of therm generally implies a purpose-built device, not one which is used for other phases (as the shuttle most certainly is!) The Soyuz resupply vessels which are typically left docked to the International Space Station (Or Alpha, or Freedom, or whatever the nom du jour is) as lifeboats are being used as simple RVs.
One other use of 'RV' is in the more military parlance. To the military, an RV tends to be the part of a ballistic missile; it is designed to protect the warheads on their way into the atmosphere over the target. The RV is released from a missile's warhead bus. MIRV systems have multiple RVs - Multiple Independently-targeted Reentry Vehicles.