1. population shift a change in the relative numbers of the different groups of individuals making up a population
  2. population scientist a scientist who studies the growth and density of populations and their vital statistics
  3. population growth increase in the number of people who inhabit a territory or state
  4. population the people who inhabit a territory or state
  5. population control control over the growth of population; a government program
  6. population profile a chart showing the number of people as a function of their ages
  7. propulsion system a system that provides a propelling or driving force
  8. ventilation shaft a shaft in a building
  9. relationship a mutual connection between people
  10. Population Commission the commission of the Economic and Social Council of the United Nations that is concerned with population control
  11. abolitionist a reformer who favors putting an end to slavery
  12. Doppler shift change in the apparent frequency of a wave as observer and source move toward or away from each other
  13. split shift a working shift divided into two periods of time with several hours in between
  14. Populus deltoides a common poplar of eastern and central United States
  15. publishing house a firm in the publishing business
  16. publishing firm a firm in the publishing business
  17. popularity contest competition (real or figurative) for popular support
  18. publishing the business of issuing printed matter for sale or distribution
  19. populist an advocate of democratic principles
  20. Populus tremuloides slender aspen native to North America