noun (n)

• the people who inhabit a territory or state(noun.group)

  Example:
  The population seemed to be well fed and clothed.
  

  source: wordnet30
• a group of organisms of the same species inhabiting a given area(noun.group)

  Example:
  They hired hunters to keep down the deer population.
  

  source: wordnet30
• (statistics) the entire aggregation of items from which samples can be drawn(noun.cognition)

  Example:
  It is an estimate of the mean of the population.
  

  Synonym:
  universe
  

  source: wordnet30
• the number of inhabitants (either the total number or the number of a particular race or class) in a given place (country or city etc.)(noun.quantity)

  Example:
  People come and go, but the population of this town has remained approximately constant for the past decade.
  The African-American population of Salt Lake City has been increasing.
  

  source: wordnet30
• the act of populating (causing to live in a place)(noun.act)

  Example:
  He deplored the population of colonies with convicted criminals.
  

  source: wordnet30
• The act or process of populating; multiplication of inhabitants.(noun)

  source: webster1913