1. right atrium the right upper chamber of the heart that receives blood from the venae cavae and coronary sinus
  2. radiothorium radioactive isotope of thorium with mass number 228
  3. red drum large edible fish found off coast of United States from Massachusetts to Mexico
  4. natatorium pool that provides a facility for swimming
  5. auditorium the area of a theater or hall where the audience sits
  6. birth trauma physical injury to an infant during the birth process
  7. red trillium trillium of northeastern United States with sessile leaves and red or purple flowers having a pungent odor
  8. left atrium the left upper chamber of the heart that receives blood from the pulmonary veins
  9. Ceratotherium African genus
  10. deuterium an isotope of hydrogen which has one neutron
  11. sudatorium a bathhouse for hot air baths or steam baths
  12. diatribe thunderous verbal attack
  13. moratorium suspension of an ongoing activity
  14. rat terrier any of several breeds of terrier developed to catch rats
  15. Uintatherium type genus of the Uintatheriidae
  16. stateroom a guest cabin
  17. side drum a small drum with two heads and a snare stretched across the lower head
  18. short-term relating to or extending over a limited period
  19. freight train a railroad train consisting of freight cars
  20. redetermine fix, find, or establish again