#calm_air  wind moving at less than 1 knot; 0 on the Beaufort scale
  supertype:  wind  air moving (sometimes with considerable force) from an area of high pressure to an area of low pressure; "trees bent under the fierce winds"; "when there is no wind, row"
  part of:  Beaufort_scale__wind_scale  an international scale of wind force from 0 (calm air) to 12 (hurricane)

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