1. improper fraction a fraction whose numerator is larger than the denominator
  2. proper fraction a fraction with a numerator smaller than the denominator
  3. imperfection the state or an instance of being flawed
  4. appropriation a deliberate act of acquisition, often without permission
  5. improvisation a performance given without planning or preparation
  6. simple fraction the quotient of two integers
  7. imprecation the act of calling down a curse that invokes evil
  8. improperness an improper demeanor
  9. compound fraction a fraction with fractions in the numerator or denominator
  10. complex fraction a fraction with fractions in the numerator or denominator
  11. imperforate anus a congenital defect of the anus
  12. impervious not admitting of passage or capable of being affected
  13. appropriate suitable for a particular person, place, or situation
  14. double refraction splitting a ray into two parallel rays polarized perpendicularly
  15. impossible action an alternative that is not available
  16. proportion relation with respect to comparative quantity or magnitude
  17. refraction the change in direction of a propagating wave
  18. angle of refraction the angle between a refracted ray and a line perpendicular to the surface between the two media at the point of refraction
  19. prevarication the deliberate act of deviating from the truth
  20. expropriation taking out of an owner's hands