1. natural spring a natural flow of ground water
  2. natural covering a natural object that covers or envelops
  3. spiral spring a spring that is wound like a spiral
  4. neutral spirits nonflavored alcohol of 95 percent or 190 proof used for blending with straight whiskies and in making gin and liqueurs
  5. thermal spring a natural spring of water at a temperature of 70 F or above
  6. transpiring that is passing through
  7. naturally occurring existing by nature and without artificial aid
  8. naturalistic representing what is real; not abstract or artificial
  9. naturalisation the proceeding whereby a foreigner is granted citizenship
  10. naturalization the proceeding whereby a foreigner is granted citizenship
  11. natural science the sciences involved in the study of the physical world and its phenomena
  12. hairspring a fine spiral spring that regulates the movement of the balance wheel in a timepiece
  13. air spring a mechanical device using confined air to absorb the shock of motion
  14. natural process a process existing in or produced by nature
  15. natural depression a sunken or depressed geological formation
  16. neutralisation action intended to nullify the effects of some previous action
  17. needle bearing bearings containing small metal balls
  18. natural fiber fiber derived from plants or animals
  19. nitrogen-bearing of or relating to or containing nitrogen
  20. natural fibre fiber derived from plants or animals