What is the meaning of naturalize?

verb

• Make into a citizen.
  • usage: "The French family was naturalized last year"
  • synonyms: naturalise
• Explain with reference to nature.
• Adopt to another place.
  • usage: "The stories had become naturalized into an American setting"
  • synonyms: naturalise
• Make more natural or lifelike.
  • synonyms: naturalise
• Adapt (a wild plant or unclaimed land) to the environment.
  • usage: "domesticate oats"; "tame the soil"
  • synonyms: domesticate, cultivate, naturalise, tame