1. 1〔速度〕speed
    • 光[音]の速さ
    • the speed of light [sound]
    • 速さを増す[落とす]
    • increase [reduce] the speed
    • 時速150キロの速さで走る
    • run at the speed [rate] of 150 kilometers an hour
    • この車はどれぐらいの速さで走れますか
    • How fast can this car go?
  1. 2〔速いこと〕
    • 彼の逃げ足の速さには舌を巻いた
    • I was astonished at the speed with which he escaped.