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. unimpressively in an unimpressive manner
  13. impersonally without warmth
  14. impersonator someone who (fraudulently) assumes the appearance of another
  15. comprehensively in an all-inclusive manner
  16. impression a vague idea in which some confidence is placed
  17. unimpressionable not sensitive or susceptible to impression
  18. unpresentable creating an unfavorable or neutral first impression
  19. impressionist relating to or characteristic of Impressionism
  20. Impressionism a school of late 19th century French painters who pictured appearances by strokes of unmixed colors to give the impression of reflected light