1. headspace the volume left at the top of a filled container (bottle or jar or tin) before sealing
  2. hold back refrain from doing
  3. hold sway be master; reign or rule
  4. hair space (printing) the narrowest of the spaces used to separate words or letters
  5. null space a space that contains no points; and empty space
  6. Hilbert space a metric space that is linear and complete and (usually) infinite-dimensional
  7. health spa a place of business with equipment and facilities for exercising and improving physical fitness
  8. cold spell a spell of cold weather
  9. hold close hold firmly, usually with one's hands
  10. hold up be the physical support of; carry the weight of
  11. hold open retain rights to
  12. hot spot a place of political unrest and potential violence
  13. feldspar any of a group of hard crystalline minerals that consist of aluminum silicates of potassium or sodium or calcium or barium
  14. cold sober totally sober
  15. hot spell a spell of hot weather
  16. holy place a sacred place of pilgrimage
  17. absolute space physical space independent of what occupies it
  18. halitosis offensive breath
  19. predispose make susceptible
  20. bold face a typeface with thick heavy lines