Forms: α. 4–6 undermyne, 5– -mine, 7 -moine (also 4–6 vnder-, 4–5 vndir-, 5 vndyr-). β. 5 vndermynden, 6 -mynde, 6–7 vnder-, underminde, 7–8 (9 dial.) undermind. [UNDER-1 4 a + MINE v. Cf. Du. ondermijnen, older Da. undermine; also MDu. ondermineren, Da. underminere, Sw. -era, G. unterminiren.
In 15th-cent. texts undermyne or -mine is occasionally miswritten for undernim.]
1. trans. To dig or excavate beneath, to make a passage or mine under (a wall, etc.), esp. as a military operation; to sap.
α. 13[?]. Coer de L., 4721. The Crystene the walles undermyne.
1382. Wyclif, Jer., li. 58. The wal of Babilon … with vndermynyng shal be vndermyned.
c. 1450. Contin. Brut, 577. And after, [they] vndermynet þe walles and þe toures, and sette shores vndernethe.
a. 1548. Hall, Chron. Hen. V., 45. Knowyng that their walles were vndermyned and shortely like to fal.
1582. N. Lichefield, trans. Castanheda’s Conq. E. Ind., I. ix. 22. It is a verye great Citie, placed … so that it cannot be undermined.
1616. J. Lane, Contn. Sqr.’s T., VII. 397. To lead his men safe to the walled towne, which vndermoine hee shoold.
1618. Bolton, Florus (1636), 181. Undermining their port Pireus, and more than six Walls of theirs.
1726. Leoni, Alberti’s Archit., I. 68. When the foundation is … on a rock, it will be in vain to think of undermining it.
1776. G. Semple, Building in Water, 40. We had no other Way to break it, but by undermining it, and then break it off in Pieces.
1834. Marryat, P. Simple, xxi. We must undermine the gate, O’Brien; we must pull up the pavement until we can creep under.
1848. Dickens, Dombey, vi. Buildings that were undermined and shaking, [were] propped by great beams of wood.
β. c. 1440. Promp. Parv., 511/1. Vndermyndyn, idem quod vnderdelvyn.
1513. Douglas, Æneid, VIII. xi. 38. Sum vndermyndand the ground with a hoill.
1571. Leslie, Hist. Scot. (Bann. Cl.), 101. [They] under myndit the neddir sole of the yett of Dunbartane.
a. 1644. Spottiswoode Misc. (1844), I. 146. In the late warrs … the churches [were] undermynded and fired.
1828–. in dial. glossaries (Yks., Linc., Surrey).
b. absol. To make excavations or mines.
1382. Wyclif, Exod. xxii. 2. If a theef brekynge an hows, or were foundun vndurmynynge.
1412–20. Lydg., Chron. Troy, II. 6335. Þei … turnen vp so doun Boþe wal & tour … Þat no þing stood, so þei vnder-myne.
1601. Holland, Pliny, II. 467. Necessarie it is … to undermine a great way by candlelight, & to make hollow vaults under the mountains.
1646. H. P., Medit. Seige, 60. It is an usuall practice to under-mine, and when they have brought the Mine unto the Works, to blow it up with powder.
1685. Travestin, Siege Newheusel, 34. This day we began to undermine on the side attackt by the Troops of Brunswick.
c. In fig. context.
c. 1400. Beryn, 3480. Ye wend … þat ye had hym engyned; But yee shul fele in every veyn þat ye be vndirmyned, And I-brouȝt at ground.
1559. Aylmer, Harborowe, C ij b. These … be … the pik-axes to vnder mynde the state.
1601. Shaks., All’s Well, I. i. 130. Man setting downe before you, will vndermine you, and blow you vp.
1668. Dryden, Tyrannic Love, III. i. Yet fierceness suits not with her gentle kind; They brave assaults, but may be undermined.
1794. Burke, Corr. (1844), IV. 254. As yet, the house is not fallen; but it is completely undermined.
1855. Motley, Dutch Rep., VI. i. III. 409. Religious fanaticism had undermined the bulwark almost as soon as reared.
1875. Jowett, Plato (ed. 2), V. 363. The fair superstructure falls because the old foundations are undermined.
2. a. Of water: To work under and wash away (ground, etc.).
1398. Trevisa, Barth. De P. R., XV. lxxxii. (Bodl. MS.). Þe parties of ilondes beþ ywasted, & vndermyned wiþ betinge of watres.
1562. Pilkington, Expos. Abdyas, Pref. 5. A strong heady streame, undermining great hygh bankes.
1610. Holland, Camden’s Brit., 676. The riveret Alen … undermineth the ground and once or twice hideth himselfe.
1707. Mortimer, Husb., 5. Alder makes an extraordinary Fence against Rivers and Streams, and preserves the Banks from being undermined by the Water.
1784. Cook’s Voy., IV. ix. II. 464. By undermining and washing away those parts that lie exposed to the surge of the sea.
1855. Orr’s Circ. Sci., Inorg. Nat., 155. The stream … .relieving the gloom of the naked rocks, and at the same time tending to undermine them.
1860. Tyndall, Glac., I. xv. 101. The glacier … is incessantly undermined,… till at length the projecting mass … tumbles into the lake.
absol. 1858. Macdonald, Phantastes, xiii. 148. The springing waters were dammed back into his soul, where, finding no utterance, they … swelled, and undermined.
b. Of animals: To burrow under or in; to make insecure, to cause to fall, through burrowing; also, to form (a passage) by burrowing.
1526. Pilgr. Perf. (W. de W., 1531), 55. Catche these lytell foxes, whiche with dyggynge of theyr dennes vndermyndeth our vynes.
1567. Maplet, Gr. Forest, 92. He hath his cabbage [= den] in the yearth with two contrary wayes vndermined to enter into it.
1579. Lyly, Euphues (Arb.), 109. In a shorte space, there was a Towne in Spayne vndermined with Connyes.
1629. Davenant, Albovine, III. i. When she [sc. the mole] undermines the earth.
1697. Dryden, Virg. Georg., IV. 355. Lizards … a dark Retreat Have found in Combs, and undermin’d the Seat.
a. 1704. T. Brown, Declam. Adverbs, Wks. 1720, I. 45. All Thessaly had in the twinkling of a Shoeing-horn been certainly undermin’d by Lobsters.
c. Path. To erode beneath the surface.
1879. St. George’s Hosp. Rep., IX. 254. Hip-joint … surrounded with œdema and undermined by sinuses.
1898. Hutchinson’s Arch. Surg., IX. 111. The chronic infective inflammations … which ulcerate to a slight extent whilst they undermine widely.
3. fig. (Cf. 1 c.) To work secretly or stealthily against (a person); to overthrow or supplant by underhand means.
α. 1430–40. Lydg., Bochas, IV. Prol. (1554), 99 b. Fortune could him vndermine That al hys wisedome stode in none auayle.
1535. Coverdale, Gen. xxvii. 36. He maye well be called Iacob, for he hath vndermined me now two tymes.
1561. T. Norton, Calvin’s Inst., IV. xviii. To beguile and vndermine an other man, al men know to be vnlawfull.
1633. P. Fletcher, Purple Isl., II. xviii. Whose pleasing sweetnesse … Doth oft the Prince himself with witch’ries undermine.
1678. Wanley, Wond. Lit. World, V. i. § 100. 468/1. Rodolphus … being undermined by his brother Matthias, was forced to surrender to him … Hungary and Bohemia.
1759. Robertson, Hist. Scot., III. Wks. 1851, I. 237. Some of his rivals he secretly undermined.
1775. Adair, Amer. Ind., 91. The religious advantages and arguments by which the French used to undermine us with the Indians.
1849. Macaulay, Hist. Eng., ii. I. 197. Those who had assailed and undermined him began to struggle for the fragments of his power.
1876. Holland, Seven Oaks, xiv. 200. Are you to sit tamely down and be undermined?
β. 1530. Palsgr., 767/1. Medyll nat with hym,… for surely he wyll undermynde the.
1596. Spenser, F. Q., V. vi. 32. He was nothing valorous, But with slie shiftes and wiles did vnderminde All noble Knights.
1613. Jackson, Creed, II. vii. § 7. Yet are they easily to be vnderminded by Sathan.
1663. Gerbier, Counsel, 103. If he be a Master workman, whom they will … suspect to have a design to underminde and supplant them.
1869–. in Eng. Dial. Dict. (Yks., Lanc., Linc.).
absol. 1584. Lyly, Sappho, I. iii. 26. Where we suspect, we vndermine.
1712. Blackmore, Creation, VII. 349. The ambitious statesman labours dark designs, Now open force employs, now undermines.
† 4. To underlie and spoil. Obs.–1
1430–40. Lydg., Bochas, I. x. (1544), 21 b. Some fresh floures haue a full bitter rote And lothsom gal can suger eke vndermine.
5. To persuade or win over, to tamper with or pervert, by subtle means. Also absol.
1457. Harding, Chron., in Eng. Hist. Rev., Oct. (1912), 747. His language … so benygne was and trewe it vndyrmyned Thair hertes hole to loue hym at thair myght.
1522. Skelton, Why not to Court? 434. So he dothe vndermynde, and such sleyghtes dothe fynde, That the kynges mynde By hym is subuerted.
1579. Lyly, Euphues (Arb.), 85. Ferardo … desired him to kepe silence, vntil he had vndermined hir by subtiltie.
1664. Dryden, Rival Ladies, IV. iii. She undermin’d my Soul With Tears.
1671. Milton, P. R., I. 179. The Father … Ventures his filial Vertue, though untri’d, Against whate’re may … Allure, or terrifie, or undermine.
† 6. a. To ascertain, or inquire, in a secret or underhand manner. Obs.
a. 1575. trans. Pol. Verg. Eng. Hist. (Camden No. 36), 56. Cæsar undermining their counsels throughe his Captives. Ibid., 80. When as Agricola hadd … undermined the purpose of his adversaries.
1596. Nashe, Saffron Walden, 82. He hath been noted … very suspitiously to vndermine, whither any man know such a fellow.
† b. To question (a person) guilefully. Obs.
1581. [A. Gilby], Test. 12 Patriarchs, 58 b. He wil talke guilefully with thee, and vndermine thee to doe thee a shrewde turne.
1599. Hakluyt, Voy., II. I. 266. There was a Dutch Jesuite … sent vnto them, to vndermine and examine them.
7. To weaken, injure, destroy or ruin, surreptitiously or insidiously.
α. 1569. (title) A Bull graunted by The Pope … to vndermyne … Allegeance to the Quene.
a. 1596. Sir T. More, I. ii. 69. I pray ye,… Goe not aboute to vndermine my life.
1641. J. Jackson, True Evang. T., II. 146. It is no fault … to undermine fraud with fraud.
1699. Burnet, 39 Art., xviii. 174. Which strikes at the Foundation, and undermines the Truth of all Revealed Religion.
1732. Berkeley, Alciphr., I. § 2. A dangerous sort of men that would undermine received principles and opinions.
1771. Junius’ Lett., lix. 272. Who is he, that has made it the study … of his life, to undermine and alter the whole system of jurisprudence?
1850. Merivale, Rom. Emp., ix. (1865), I. 384. The authority of the nobles as a class had been completely undermined.
1884. Ruskin, Pleas. Eng., 16. These controversies vexed and shook, but never undermined, the faith they strove to purify.
β. 1565. Stapleton, trans. Staphylus’ Apol., 152. To vnderminde Christendom.
1694. R. Burthogge, Reason, 110. The Ground of this underminded, and the nature of the Divine Omnipresence represented.
1726. Cavallier, Mem., Ded. p. iv. Their Civil and Religious Liberties, which after having been artfully underminded by several preceding Princes, were at last totally subverted.
b. To weaken or destroy (the health or constitution) by degrees; to sap.
1812. Crabbe, Tales, II. 417. Augmented pay procured him decent wealth, But years advancing undermined his health.
1843. R. J. Graves, Syst. Clin. Med., xxv. 319. Mercury may be given … in such a manner as gradually to undermine the constitution.
1860. J. M. Carnochan, Operat. Surg., 61. The constitution became … undermined [by ostitis].
Hence Undermined ppl. a.
1844. P. Parley’s Ann., V. 13 The undermined bank of some river.
1899. Allbutt’s Syst. Med., VIII. 801. On examination of the undermined skin and granulations.
