1. benefactress a woman benefactor
  2. benefactor a person who helps people or institutions
  3. perfunctory hasty and without attention to detail; not thorough
  4. rubber tire a tire consisting of a rubber ring around the rim of an automobile wheel
  5. rubber tree small genus of South American trees yielding latex
  6. prefecture the district administered by a prefect
  7. perfect gas a hypothetical gas with molecules of negligible size that exert no intermolecular forces
  8. perfecter a skilled worker who perfects something
  9. refractoriness the trait of being unmanageable
  10. prime factor the prime factors of a quantity are all of the prime quantities that will exactly divide the given quantity
  11. refractory stubbornly resistant to authority or control
  12. rhesus factor a blood group antigen possessed by Rh-positive people
  13. perfunctorily in a set manner without serious attention
  14. Rh factor a blood group antigen possessed by Rh-positive people
  15. prefectural of or relating to a prefecture
  16. reflectorise provide with reflectors, such as chemicals
  17. factorise resolve (a polynomial) into factors
  18. car factory a factory where automobiles are manufactured
  19. rubbernecker a person who stares inquisitively
  20. robber frog of southwest United States and Mexico