1883 Harper's Mag. Jan. 201/1 In about an hour the undercut had approached the heart of the tree.

1892 R. 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.

1923 J. B. Parfitt Operative Dental Surg. (ed. 2) x. 87 The condition for retention, namely, some kind of ‘undercut’, has already been fulfilled.

1980 J. R. Grundy Conservative Dentistry vii. 41/1 Minor undercuts should be removed during cavity preparation.

1892 Trans. Federated Inst. Mining Engineers I. 130 (table) Depth of undercut.

1902 A. 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.

1939 B. L. Coombes These Poor Hands vii. 109 With such a large undercut there was the likelihood of it [sc. the roof] falling any second.

1959 G. 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.

1914 A. E. Ingham Gearing i. 32 If, however, pinions having a low number of teeth are constructed, they are much more undercut below the base line than is consistent with strength or with tooth contact. This ‘undercut’ or ‘interference’ is clearly shown in Fig. 11.

1964 F. O'Rourke Mule for Marquesa iii. 58 Fardan found an under~cut in the south wall two miles from the mouth.

1971 Country 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.

1977 Design 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.

1598 J. Florio Worlde of Wordes Sottotagliare, to vnder-cut.

1725 R. Bradley Chomel's Dictionaire Œconomique at Turfing Spade Its of very great Use to some to undercut the Turf, after it is mark'd out with the Trenching Plough.

1881 J. Geikie Prehist. Europe 71 Cliffs of homogeneous composition are often undercut by streams.

1874 J. Ruskin Val D'Arno App., in Wks. IX. 228 He has undercut his Madonna's profile..too delicately for time to spare.

1875 T. Seaton Man. Fret Cutting 61 You must now commence to back carve the whole; that is to say, to undercut the leaves, stems, and branches.

1891 Cent. Dict.

1926 E. Bowen Ann Lee's 86 Mr. Barlow..walked springily about..hacking, slashing, and under-cutting with his racquet at the air.

1883 W. S. Gresley Gloss. Terms Coal Mining 135 Hole, to undercut a seam of coal, &c., by chipping away the coal, &c., with a pick.

1892 Trans. 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.

1939 B. L. Coombes These Poor Hands vii. 108 It [sc. the coal-cutter] undercut the coal to the depth of the jib.

1945 D. 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.

1982 Sci. 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.

1884 Manch. Examiner 30 July 5/2 We do not want the Post Office to ‘undercut’ private agencies at the expense of the national taxpayer.

1886 E. Lynn Linton in Fortn. Rev. Oct. 500 They are able to undercut the men, and can afford to work for less.

1911 H. S. Harrison Queed xxx. 390 Lodgings..which heavily undercut Mrs. Paynter's modest prices.

1955 W. J. Bate Achievem. of S. Johnson ii. 81 In the very activity or process of wishing, there are inherent liabilities that are able to undercut the wish itself.

1976 National 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.

1977 L. Gordon Eliot's Early Years iii. 63 The wry, derisive note..undercuts the posturing of Saint Narcissus.

1981 R. Hayman K: Biogr. Kafka xi. 146 He was aware of undercutting all his gestures towards healthy living by starving himself of sleep.