What is the meaning of lowering?

noun

• The act of causing to become less.
• The act of causing something to move to a lower level.
  • synonyms: letting down

verb

• Move something or somebody to a lower position.
  • usage: "take down the vase from the shelf"
  • synonyms: lower, take down, let down, get down, bring down
• Set lower.
  • usage: "lower a rating"; "lower expectations"
  • synonyms: lower, lour
• Make lower or quieter.
  • usage: "turn down the volume of a radio"
  • synonyms: turn down, lower, lour
• Cause to drop or sink.
  • usage: "The lack of rain had depressed the water level in the reservoir"
  • synonyms: lower, depress
• Look angry or sullen, wrinkle one's forehead, as if to signal disapproval.
  • synonyms: frown, glower, lour, lower

adjective

• Darkened by clouds.
  • usage: "a heavy sky"
  • synonyms: heavy, sullen, threatening