What is the meaning of occupation?

noun

• The principal activity in your life that you do to earn money.
  • usage: "he's not in my line of business"
  • synonyms: business, job, line of work, line
• The control of a country by military forces of a foreign power.
  • synonyms: military control
• Any activity that occupies a person's attention.
  • usage: "he missed the bell in his occupation with the computer game"
• The act of occupying or taking possession of a building.
  • usage: "occupation of a building without a certificate of occupancy is illegal"
  • synonyms: occupancy, moving in
• The period of time during which a place or position or nation is occupied.
  • usage: "during the German occupation of Paris"