Definition of undermine in English:

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Pronunciation: /ʌndəˈmʌɪn/


[with object]
1Erode the base or foundation of (a rock formation): the flow of water had undermined pillars supporting the roof
More example sentences
  • The lighthouse stands on a plinth of rock undermined by caves, perhaps once used by smugglers.
erode, wear away, eat away at, chip away, undercut
1.1Dig or excavate beneath (a building or fortification) so as to make it collapse: the demolition engineers did eventually undermine two of the tower’s six sides
More example sentences
  • Within days, the French advanced into the city outskirts and undermined numerous buildings.
  • The Romans also developed tunnelling for military purposes, either by breaking through behind enemy defences or by undermining fortifications to cause their collapse.
  • The disaster was caused by the total collapse of his house in the Rue d' Anjou, undermined by the excavations carried out by the bank next door for its strong room.
tunnel under, dig under, burrow under, excavate, sap
2Lessen the effectiveness, power, or ability of, especially gradually or insidiously: this could undermine years of hard work
More example sentences
  • What they don't understand is that being boring limits their power and undermines their effectiveness.
  • And yet, the way he handled the events that followed gradually undermined his position.
  • They might have to share power and that is dangerous because it would undermine their position of power.
subvert, sabotage, threaten, weaken, compromise, diminish, reduce, impair, mar, spoil, ruin, impede, hinder, damage, hurt, injure, cripple, disable, enfeeble, sap, shake;
whittle away, eat away
informal foul up, botch, put the kibosh on, drag through the mud
British informal throw a spanner in the works of, queer the pitch of
North American informal throw a monkey wrench in the works of



Example sentences
  • That would be on account of my false self, my twin, my judge, unhappy anima and underminer.
  • Once again, these underminers of our foreign policy are doing more harm to our country.
  • So you see yourself as an underminer of the system?


Middle English: from under- + the verb mine2, probably suggested by Middle Dutch ondermineren.

Words that rhyme with undermine

align, assign, benign, brine, chine, cline, combine, condign, confine, consign, dine, divine, dyne, enshrine, entwine, fine, frontline, hardline, interline, intertwine, kine, Klein, line, Main, malign, mine, moline, nine, on-line, opine, outshine, pine, Rhein, Rhine, shine, shrine, sign, sine, spine, spline, stein, Strine, swine, syne, thine, tine, trine, twine, Tyne, underline, vine, whine, wine

For editors and proofreaders

Line breaks: under|mine

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