| 释义 |
ˈknife-ˌedge
1. The edge of a knife; also transf., anything keenly cutting. Also attrib. = knife-edged.
1876Geo. Eliot Dan. Der. xxiii, Her pride had felt a terrible knife-edge. 1877E. R. Conder Bas. Faith ii. 80 To insert the knife-edge of a sharp discrimination. 1884Tennyson Becket ii. i. 140, I would creep, crawl over knife-edge flint Barefoot. a1930D. H. Lawrence Last Poems (1932) 39 The sudden dripping down of the knife-edge cleavage of the lightning. a1935T. E. Lawrence Mint (1955) ii. xii. 132 He creases everybody's trousers with the knife-edge that Stiffy demands. 1969Sci. Jrnl. Nov. 35/2 Steel wheels or even solid rubber tyres..give a knife-edge response which would render driving at speeds over 80 km/h impossibly dangerous.
2. a. A wedge of hard steel, on which a pendulum, scale-beam, or the like, is made to oscillate.
1818Capt. Kater in Phil. Trans. 35 For the construction of the pendulum, it became of..importance to select a mode of suspension..free from objection. Diamond points, spheres, and the knife edge, were each considered. 1851Illustr. Catal. Gt. Exhib. 1266 The pendulum is suspended on a knife-edge of very hard bronze. 1854J. Scoffern in Orr's Circ. Sc., Chem. 4 Delicate balances have their points of oscillation composed of a steel knife-edge working on agate planes.
b. transf. and fig. Esp. a sharp crest of rock, ice, sand, or the like. Also attrib., as knife-edge ridge.
1871L. Stephen Playgr. Europe v. (1894) 120 Balancing ourselves on a knife-edge of ice between two crevasses. 1897Pall Mall Mag. Aug. 524 She had come to the party..on the knife-edge of anticipation and alarm. 1907Westm. Gaz. 26 Nov. 3/2 The road thereto lies along a ‘knife-edge’. 1925W. J. Miller Introd. Physical Geol. viii. 252 A knife-edge ridge may also develop where glaciers in two parallel valleys erode and steepen the valley sides until only a very sharp divide separates the valleys. 1925E. F. Norton Fight for Everest, 1924 i. ii. 31 A ridge which begins in a knife-edge of rock worthy of the Chamounix Aiguilles. 1945Baker Austral. Lang. iii. 58 Knife edges, as certain razor-back sandhills are known. 1963Times 24 Jan. 10/3 Mr. John Brass, chairman of the West Midlands Division of the N.C.B., said yesterday that west Midland coal supplies were poised ‘on a knife edge’ at the present. 1964C. Willock Enormous Zoo v. 74 The immediate foreground beneath the sandstone cliff..was eroded into a series of gullies and knife-edges like row upon row of yellowed shark's teeth. 1969C. R. Longwell et al. Physical Geol. xii. 266/2 An arête is a jagged, knife-edge ridge created where two groups of cirque glaciers have eaten into the ridge from both sides. 1971Country Life 25 Feb. 408/3 The ridge goes easily at first on firm snow..and finally ends in a snow knife-edge. 1972Guardian 18 Feb. 24/5 The Government's knife-edge victory for the European Communities Bill in the Commons last night. 1974Times 12 Oct. 1/1 A government with a knife-edge majority. Ibid. 1/2 Mr Wilson intends to govern on a parliamentary knife-edge for at least two or three years.
3. Diamond-cutting. (See quot.)
1909J. Wodiska Bk. Precious Stones 349 Knife-edge. The girdle of a brilliant cut to a sharp edge and polished.
Hence knife-edged a., having a thin sharp edge like a knife.
1863–76T. B. Curling Dis. Rectum (ed. 4) 46 A pair of knife-edged scissors. 1865Geikie Scen. & Geol. Scot. vi. 118 A mere knife-edged crest, shelving steeply into the glens on either side. 1883Harper's Mag. Aug. 445/2 A knife-edged craft with wide keel. |