| 释义 |
▪ I. ˈundercut, n.
[under-1 5 b and 4 d.]
1. The under-side of a sirloin of beef.
1859Habits of Gd. Society v. 223 The sirloin has an upper and an under cut, about which tastes differ. 1890Mrs. Beeton Cookery Bk. 165 The undercut, or fillet of a sirloin, is best eaten when hot.
2. a. U.S. A cut made in the trunk of a tree on the side towards which it is intended to fall.
Several other technical senses are recorded in modern American dictionaries.
1883Harper's Mag. Jan. 201/1 In about an hour the undercut had approached the heart of the tree.
b. Dentistry. A horizontal cut at the base of a tooth cavity; esp. one made to anchor a filling more securely.
1892R. Ottolengui Methods of filling Teeth i. 6 Many fillings have failed through the well-meant but unwise efforts of the operator to give great retentive strength to his cavity by deep undercuts. 1923J. B. Parfitt Operative Dental Surgery (ed. 2) x. 87 The condition for retention, namely, some kind of ‘undercut’, has already been fulfilled. 1980J. R. Grundy Conservative Dentistry vii. 41/1 Minor undercuts should be removed during cavity preparation.
c. Mining. A long, thin cut made under a vein of ore or a face of coal. Cf. overcut n. c.
1892Trans. Federated Inst. Mining Engineers I. 130 (table) Depth of undercut. 1902A. S. E. Ackermann Coal-Cutting by Machinery in Amer. ii. 31 They hole about 2in. in the clay, and partly because of this and partly because of two dirt bands at the bottom, they got practically the whole of the coal taken out of the undercut. 1939B. L. Coombes These Poor Hands vii. 109 With such a large undercut there was the likelihood of it [sc. the roof] falling any second. 1959G. D. Mitchell Sociol. viii. 136 Gummers..clean out the undercut so that when the shot is fired the coal will have space in which to fall.
d. gen. A space formed by the removal or absence of material from the lower part of something.
1914[see interference 5 b (i)]. 1964F. O'Rourke Mule for Marquesa iii. 58 Fardan found an under⁓cut in the south wall two miles from the mouth. 1971Country Life 15 July 141/3 Some sickness has made them lie out of sight in one of those undercuts that sheep rub for themselves in an eroding bank of light soil. 1977Design. Engin. July 54/2 In load bearing applications, undercuts, knurls, lugs, and dovetails are used to provide the component with surfaces onto which the molten metal can lock as it shrinks.
3. A projection on a pattern corresponding to an undercut portion of the mould.
1909in Cent. Dict. Suppl. 1935Die-Casting (Machinery's Yellow Back Series No. 4) i. 10 To provide the undercut a collapsible core is necessary.
Add:4. Sport. Underspin; also, a stroke or shot which imparts this to the ball.
1920E. R. Wilson in P. F. Warner Cricket ii. 84 Back spin is undercut applied to the back half of the ball, and is more easily put on with a low action. 1960Times 24 June 20/3 He switched his top-spin backhand to a nasty undercut.
▪ II. underˈcut, v.
[under-1 4 a and 8 b.]
†1. trans. To cut down or cut off. Obs.
1382Wyclif Isaiah xxxviii. 12 Kut of is as of a weuere my lif; whil ȝit I weuede, he under kutte me.
2. a. To cut (away) below or beneath.
1598Florio, Sottotagliare, to vnder-cut. 1725Fam. Dict. s.v. Turfing Spade, Its of very great Use to some to undercut the Turf, after it is mark'd out with the Trenching Plough. 1881J. Geikie Prehist. Europe 71 Cliffs of homogeneous composition are often undercut by streams.
b. spec. To cut or carve so as to leave the upper or exposed portion larger than the under or hidden part.
1874Ruskin Val D'Arno (1886) 141 He has undercut his Madonna's profile..too delicately for time to spare. 1875T. Seaton Fruit-Cutting 61 You must now commence to back carve the whole; that is to say, to undercut the leaves, stems, and branches.
c. Golf. To strike (a ball) below the centre, causing it to rise high in the air. Also in Lawn Tennis, to impart backspin to (the ball) by slicing down on it below the centre (in quot. absol., to play a stroke which would have this effect).
1891Cent. Dict. 1926E. Bowen Ann Lee's 86 Mr. Barlow..walked springily about..hacking, slashing, and under-cutting with his racquet at the air.
d. Mining. To cut away the under-part of (a vein of ore or a face of coal); to obtain (coal, etc.) in this way.
1883Gresley Gloss. Coal-m. 135 Hole, to undercut a seam of coal, &c., by chipping away the coal, &c., with a pick. 1892Trans. Federated Inst. Mining Engineers I. 130 The function of all these machines is to undercut the coal in the same way as has hitherto been done by hand labour. 1939B. L. Coombes These Poor Hands vii. 108 It [sc. the coal-cutter] undercut the coal to the depth of the jib. 1945D. H. Rowlands Coal xiii. 172 The very first coal-cutter was patented in the eighteenth century, and since then hundreds of inventors have worked on the problem of undercutting the coal⁓face. 1982Sci. Amer. Sept. 66/1 By the end of World War II 90 percent of the coal mined in the U.S. was undercut by machine.
3. a. To supplant by working for lower wages or payment, or by selling at lower prices.
1884Manch. Exam. 30 July 5/2 We do not want the Post Office to ‘undercut’ private agencies at the expense of the national taxpayer. 1886Mrs. E. Lynn Linton in Fortn. Rev. Oct. 500 They are able to undercut the men, and can afford to work for less.
b. fig. To render unstable; to render less firm, to undermine.
1955W. J. Bate Achievement Sam. Johnson ii. 81 In the very activity or process of wishing, there are inherent liabilities that are able to undercut the wish itself. 1976National Observer (U.S.) 13 Nov. 1/3 Many vowed that their children would not grow up with the same sort of expectations and handicaps that had so undercut their own self-reliance. 1977L. Gordon Eliot's Early Years iii. 63 The wry, derisive note..undercuts the posturing of Saint Narcissus. 1981R. Hayman K. xi. 146 He was aware of undercutting all his gestures towards healthy living by starving himself of sleep.
▪ III. ˈundercut, ppl. a.
[f. prec.]
1. Cut or carved so as to have material removed from beneath the surface. (Cf. prec. 2 b.)
1793Smeaton Edystone L. §39 The hole was somewhat under-cut; so that, when the lead was poured in, the whole together would make a sort of dovetail engraftment. 1853Rock Ch. of Fathers III. i. 111 Their slight open skreen⁓work looks but a frame for the deeply undercut thin foliage roving every where about it. a1878Sir G. Scott Lect. Archit. (1879) II. 187 They are most wonderfully carved, the leaves being so much undercut as in places to be quite detached.
2. In Lawn Tennis, applied to a stroke which undercuts or imparts backspin to the ball.
1920[see chop n.1 4 e]. 1977New Yorker 10 Oct. 152/2 He shifted from his usual top-spin backhand to a sliced undercut backhand—a stroke that many of us had seen him use only rarely.
3. Mountaineering. Of a handhold: cut from below, and used esp. to maintain balance when climbing.
1950tr. Mountaineering Handbk. (Assoc. Brit. Members Swiss Alpine Club) vi. 46 Hand and footholds make progress possible... They can be horizontal, oblique, vertical or undercut. 1965A. Blackshaw Mountaineering vi. 161 Side-holds and undercut holds are valuable for maintaining balance or for moving ‘in opposition’. 1975W. Unsworth Encycl. Mountaineering 120/1 An undercut hold is one that is upside down, but it can be useful. |