1. frightful provoking horror
  2. effortful requiring great physical effort
  3. frightfully used as intensifiers
  4. unfruitful not fruitful; not conducive to abundant production
  5. fruitful productive or conducive to producing in abundance
  6. fretful nervous and unable to relax
  7. insightful exhibiting clear and deep perception
  8. artful not straightforward or candid
  9. unforesightful lacking foresight or scope
  10. rightful legally valid
  11. affright cause fear in
  12. affirmatively in an affirmative manner
  13. foresightful planning prudently for the future
  14. worthful having worth or merit or value
  15. forgetful (of memory) deficient in retentiveness or range
  16. grateful feeling or showing thankfulness
  17. eventful characterized by many noteworthy happenings or incidents
  18. fruitfully in a productive way
  19. fretfully in a fretful manner
  20. wistful showing pensive sadness

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