What is the meaning of complication?

noun

• The act or process of complicating.
• A situation or condition that is complex or confused.
  • usage: "her coming was a serious complication"
• Any disease or disorder that occurs during the course of (or because of) another disease.
  • usage: "bed sores are a common complication in cases of paralysis"
• A development that complicates a situation.
  • usage: "the court's decision had many unforeseen ramifications"
  • synonyms: ramification
• Puzzling complexity.
  • synonyms: complicatedness, knottiness, tortuousness