What is the meaning of turn around?

noun

• Turning in an opposite direction or position.
  • usage: "the reversal of the image in the lens"
  • synonyms: reversal

verb

• Turn abruptly and face the other way, either physically or metaphorically.
  • usage: "He turned around to face his opponent"; "My conscience told me to turn around before I made a mistake"
  • synonyms: swing around, swing about
• Improve dramatically.
  • usage: "The new strategy turned around sales"; "The tutor turned around my son's performance in math"
• Improve significantly; go from bad to good.
  • usage: "Her performance in school picked up"
  • synonyms: pick up