noun (n)

• the ratio of live births in an area to the population of that area; expressed per 1000 population per year(noun.time)

  Synonym:
  birth rate, birthrate, fertility rate, natality
  

  source: wordnet30
• the state of being fertile; capable of producing offspring(noun.state)

  Synonym:
  fecundity
  Antonym:
  infertility, sterility
  

  source: wordnet30
• the property of producing abundantly and sustaining vigorous and luxuriant growth(noun.attribute)

  Synonym:
  prolificacy, rankness, richness
  

  source: wordnet30
• The state or quality of being fertile or fruitful; fruitfulness; productiveness; fecundity; richness; abundance of resources; fertile invention; quickness; readiness; as, the fertility of soil, or of imagination.(noun)

  source: webster1913