What is the meaning of loosen up?

verb

• Cause to become unblocked.
  • usage: "The medicine unstuffed my nose in minutes"
  • synonyms: unstuff
• Become less tense, less formal, or less restrained, and assume a friendlier manner.
  • usage: "our new colleague relaxed when he saw that we were a friendly group"
  • synonyms: relax
• Make one's body limber or suppler by stretching, as if to prepare for strenuous physical activity.
  • synonyms: limber up, warm up
• Become less tense, rest, or take one's ease.
  • usage: "He relaxed in the hot tub"; "Let's all relax after a hard day's work"
  • synonyms: relax, unbend, unwind, decompress, slow down
• Cause to feel relaxed.
  • usage: "A hot bath always relaxes me"
  • synonyms: relax, unstrain, unlax, unwind, make relaxed