blow·hole /-ˌhol/
  噴水孔,通風孔,通氣孔
  Blow·hole n.
  1. A cavern in a cliff, at the water level, opening to the air at its farther extremity, so that the waters rush in with each surge and rise in a lofty jet from the extremity.
  2. A nostril or spiracle in the top of the head of a whale or other cetacean.
  Note: ☞ There are two spiracles or blowholes in the common whales, but only one in sperm whales, porpoises, etc.
  3. A hole in the ice to which whales, seals, etc., come to breathe.
  4. Founding An air hole in a casting.
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  blowhole
       n 1: the spiracle of a cetacean located far back on the skull
       2: a hole for the escape of gas or air [syn: vent, venthole,
           vent-hole]