What is the meaning of exacting?

verb

• Claim as due or just.
  • usage: "The bank demanded payment of the loan"
  • synonyms: demand, exact
• Take as an undesirable consequence of some event or state of affairs.
  • usage: "the accident claimed three lives"; "The hard work took its toll on her"
  • synonyms: claim, take, exact

adjective

• Having complicated nutritional requirements; especially growing only in special artificial cultures.
  • usage: "fastidious microorganisms"; "certain highly specialized xerophytes are extremely exacting in their requirements"
  • synonyms: fastidious
• Severe and unremitting in making demands.
  • usage: "an exacting instructor"; "a stern disciplinarian"; "strict standards"
  • synonyms: stern, strict
• Requiring precise accuracy.
  • usage: "an exacting job"; "became more exigent over his pronunciation"
  • synonyms: exigent