1. instructions a manual explaining how to install or operate a device
  2. interaction mutual or reciprocal dealings or influence
  3. weak interaction (physics) an interaction between elementary particles involving neutrinos or antineutrinos that is responsible for certain kinds of radioactive decay; mediated by intermediate vector bosons
  4. inference a conclusion you can draw based on known evidence
  5. infraction a violation of a law or rule
  6. infernal region the abode of Satan and the forces of evil
  7. insulin reaction hypoglycemia produced by excessive insulin in the system causing coma
  8. conversion reaction a mental disorder characterized by the conversion of mental conflict into somatic forms (into paralysis or anesthesia having no apparent cause)
  9. interdiction authoritative prohibition
  10. confrontation discord resulting from a clash of ideas or opinions
  11. endoergic reaction a nuclear reaction occurring with absorption of energy
  12. interrogation an instance of questioning
  13. interactional capable of acting on or influencing each other
  14. inferior rectus the ocular muscle whose contraction turns the eyeball down and medially
  15. instruction activities that impart knowledge or skill
  16. information knowledge acquired through study or experience
  17. inverse function a function obtained by expressing the dependent variable of one function as the independent variable of another; f and g are inverse functions if f(x)=y and g(y)=x
  18. interjection an abrupt emphatic exclamation expressing emotion
  19. infarction localized necrosis resulting from obstruction of the blood supply
  20. interconnection a state of being connected reciprocally