1. imperative requiring attention or action
  2. impressively in an impressive manner
  3. impressionable easily influenced
  4. imperceptible impossible or difficult to sense
  5. impersonal not relating to or responsive to individuals
  6. impressive making a strong or vivid mental image
  7. impersonate pretend to be someone you are not
  8. imperceptibly in a manner that is difficult to discern
  9. imperatively in an imperative and commanding manner
  10. imprisoned being in captivity
  11. ampersand a punctuation mark (&) that represents the conjunction "and"
  12. impersonally without warmth
  13. impersonator someone who (fraudulently) assumes the appearance of another
  14. impressionist relating to or characteristic of Impressionism
  15. impression a vague idea in which some confidence is placed
  16. unpresentable creating an unfavorable or neutral first impression
  17. Impressionism a school of late 19th century French painters who pictured appearances by strokes of unmixed colors to give the impression of reflected light
  18. impressionistic of or relating to or based on an impression rather than on facts or reasoning
  19. impressible easily impressed or influenced
  20. impregnable incapable of being attacked or tampered with