blow-hole
(ˈbləʊhəʊl)
[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 I. Platts Bk. Curios. 205 A double opening, called the spout-holes, or blow-holes. 1861 J. Lamont Seahorses v. 75 They give one spout from their blow-holes, take one breath of fresh air..and then they are all down. |
2. = air-hole 2.
| 1691 T. H[ale] Acc. New Invent. 96 Certain defects in Cast-lead..called by the Plumber Blow-holes. 1878 Ure's Dict. Arts IV. 835 The following experiments were made in order to prepare solid steel without blow-holes by the crucible process. 1906 Westm. Gaz. 29 Aug. 2/1 The way to prevent steel rusting..is to have no blow-holes. 1960 Jrnl. Iron & Steel Inst. CXCV. 223/2 (title) Blowholes in castings, and methods of preventing their occurrence. |
3. A hole through which air or gas escapes (see quots.); spec. for the escape of foul air from underground passages, of steam from railway tunnels, etc. Also = puffing-hole.
| 1858 John Shaw Gallop to Antipodes vii. 131 That is a blowhole. Don't you see the water forced into the air, like a whale spouting?.. You will see the water first and afterwards you will hear the report. 1872 [see puffing vbl. n. 5]. 1875 I. L. Bird Sandwich Isl. (1880) 56 An intermittent jet of lava..kept cooling round what was possibly a blow⁓hole. 1883 Pall Mall G. 1 June, The erection of the blow-holes on the Embankment. 1884 Ibid. 15 Mar. 2/2 Can no doubt ‘construct’ the Parks Railway without blowholes. 1891 R. Wallace Rural Econ. Austral. & N.Z. i. 24 Here also the cavernous condition of the subjacent rocks extended, and every here and there was a large pit or depression like a deserted quarry which had fallen in. From some of these so-called ‘blow-holes’ water could be pumped for the stock in dry seasons. 1938 Times 7 Sept. 9/1 He..crawled in through the ‘blow-hole’ [of a barrage-balloon] to look for leaks and examine the pressure valve. 1958 Armstrong & Roberts Illustr. Ice Gloss. ii. 91 Blow-hole, opening through a snow bridge into a crevasse or system of crevasses which are otherwise sealed by snow bridges. 1961 J. Challinor Dict. Geol. 24/1 Blow-hole, a natural chimney, on a coast, reaching from the inner end of a cave to the surface of the ground above. 1962 Listener 11 Jan. 57/2 The whole thermal area of the North Island [of New Zealand], with its hot pools and geysers and blowholes. |
4. A hole in the ice to which whales and seals come to breathe.