What is the meaning of thinning?

noun

• The act of diluting something.
  • usage: "the cutting of whiskey with water"; "the thinning of paint with turpentine"
  • synonyms: cutting

verb

• Lose thickness; become thin or thinner.
  • synonyms: thin
• Make thin or thinner.
  • usage: "Thin the solution"
  • synonyms: thin
• Lessen the strength or flavor of a solution or mixture.
  • usage: "cut bourbon"
  • synonyms: dilute, thin, thin out, reduce, cut
• Take off weight.
  • synonyms: reduce, melt off, lose weight, slim, slenderize, thin, slim down