1. flightless bird flightless birds having flat breastbones lacking a keel for attachment of flight muscles: ostriches; cassowaries; emus; moas; rheas; kiwis; elephant birds
  2. flight of stairs a stairway between one floor or landing and the next
  3. lightlessness total absence of light
  4. flightless incapable of flying
  5. weightlessness the property of being comparatively small in weight
  6. field sport a sport that is played outdoors
  7. faultlessness the quality of being without an error or fault
  8. Little Sparrow French cabaret singer (1915-1963)
  9. fool's paradise an illusory state of wellbeing
  10. flight strip an airfield without normal airport facilities
  11. frilled lizard large arboreal insectivorous Australian lizard with a ruff of skin around the neck
  12. flight of steps a stairway between one floor or landing and the next
  13. lightly armored equipped with armor heavy enough to provide protection against fire from light arms
  14. flight surgeon a medical officer specializing in aviation medicine
  15. fruitlessness the quality of yielding nothing of value
  16. beardless iris any of numerous wild or cultivated irises having no hairs on the drooping sepals (the falls)
  17. guiltlessness a state of innocence
  18. philatelist a collector and student of postage stamps
  19. light speed the speed at which light travels in a vacuum
  20. gallows bird a person who deserves to be hanged