What is the meaning of set off?

verb

• Put in motion or move to act.
  • usage: "trigger a reaction"; "actuate the circuits"
  • synonyms: trip, actuate, trigger, activate, spark off, spark, trigger off, touch off
• Leave.
  • usage: "The family took off for Florida"
  • synonyms: depart, part, start, start out, set forth, set out, take off
• Direct attention to, as if by means of contrast.
  • usage: "This dress accentuates your nice figure"; "I set off these words by brackets"
  • synonyms: bring out
• Cause to burst with a violent release of energy.
  • usage: "We exploded the nuclear bomb"
  • synonyms: explode, detonate, blow up
• Make up for.
  • usage: "His skills offset his opponent's superior strength"
  • synonyms: cancel, offset
• Set in motion or cause to begin.
  • usage: "The guide set the tour off to a good start"
• Provoke or stir up.
  • usage: "incite a riot"; "set off great unrest among the people"
  • synonyms: incite, instigate, stir up