[See BLOW v.1 5.]
1. Each of the two holes (constituting the nostrils) at the top of the head in whales and other cetaceans, through which they breathe or ‘blow.’
1787. Hunter, in Phil. Trans., LXXVII. 380. The blow-holes are two in number in many, in others only one.
1822. J. Platts, Bk. Curiosities, 205. On the upper part of the head there is a double opening, called the spout-holes, or blow-holes.
1861. J. Lamont, Seasons w. Sea-horses, v. 82. They give one spout from their blow holes, take one breath of fresh air … and then they are all down.
† 2. = AIR-HOLE 2. Obs.
1691. T. H[ale], Acc. New Invent., 96. Certain defects in Cast-lead … called by the Plumber Blow-holes.
3. A hole through which air or gas escapes; spec. for the escape of foul air from underground passages, of steam from railway tunnels, etc.
1875. Miss Bird, Sandwich Isl. (1880), 56. An intermittent jet of lava … kept cooling round what was possibly a blowhole.
1883. Pall Mall Gaz., 1 June, 12/2. The erection of the blowholes on the Embankment was, undoubtedly, a mischievous proceeding. Ibid. (1884), 15 March, 2/2. Sir John Hawkshaw can no doubt ‘construct’ the Parks Railway without blowholes.
4. A hole in the ice to which whales and seals come to breathe.
