1. reductio ad absurdum (reduction to the absurd) a disproof by showing that the consequences of the proposition are absurd; or a proof of a proposition by showing that its negation leads to a contradiction
  2. reductivism an art movement in sculpture and painting that began in the 1950s and emphasized extreme simplification of form and color
  3. reductionism a theory that all complex systems can be completely understood in terms of their components
  4. reductionist of a theory explaining complex things by simpler elements
  5. theater of the absurd plays stressing the irrational or illogical aspects of life, usually to show that modern life is pointless
  6. radioactive dust the radioactive particles that settle to the ground after a nuclear explosion
  7. reproductive system organs and tissues involved in the production and maturation of gametes and in their union and subsequent development as offspring
  8. radioactive waste useless radioactive materials that are left after some laboratory or commercial process is completed
  9. reduction division (genetics) cell division that produces reproductive cells in sexually reproducing organisms; the nucleus divides into four nuclei each containing half the chromosome number (leading to gametes in animals and spores in plants)
  10. eutectoid steel a steel that contains 0.9% carbon
  11. dictatorship a form of government in which the ruler is unconstrained
  12. reductase an enzyme that catalyses the biochemical reduction of some specified substance
  13. deductive reasoning reasoning from the general to the particular
  14. absurd inconsistent with reason or logic or common sense
  15. reduction gear gearing that reduces an input speed to a slower output speed
  16. corrugated board cardboard with corrugations
  17. consortium a cooperative association among institutions or companies
  18. reductant a substance capable of bringing about the reduction of another substance as it itself is oxidized; used in photography to lessen the density of a negative or print by oxidizing some of the loose silver
  19. redactor someone who puts text into appropriate form for publication
  20. predictability the capacity to be known or expected in advance