What is the meaning of fertility?

noun

• The ratio of live births in an area to the population of that area; expressed per 1000 population per year.
  • synonyms: birthrate, birth rate, fertility rate, natality
• The state of being fertile; capable of producing offspring.
  • synonyms: fecundity
• The property of producing abundantly and sustaining vigorous and luxuriant growth.
  • usage: "he praised the richness of the soil"; "weeds lovely in their rankness"
  • synonyms: richness, rankness, prolificacy