undermine

present singular third person undermines · participle present undermining · participle past undermined · past undermined

1. To dig underneath (something), to make a passage for destructive or military purposes; to sap.First known use 14th c.

   Martin, for instance, had on one occasion undermined a tree sacred to old gods, then stood in the path of its fall, but forced it to fall elsewhere by making the sign of the Cross.

   2009, Diarmaid MacCulloch, A History of Christianity, Penguin, published 2010, page 312

2. figurativelyTo weaken or work against; to hinder, sabotage.First known use 15th c.

   The war efforts were undermined by the constant bickering between the allies.

   4 more examples

   The penile mishaps (one involving a bristled toothbrush), severings (one involves hungry ducks) and surgeries cited by Ms. Roach are nothing if not memorable, but her book consistently undermines its own discoveries.

   2008 April 7, Janet Maslin, “A Sex Researcher Walks Into a Lab, and Then Things Start to Get Comical”, in The New York Times, archived from the original on 26 Nov 2022

   The growing use of social media to spread anger and dissent in the Arab world has been hailed by western governments as one of the chief justifications for a completely unfettered internet. The US is reportedly funding the secret rollout of technology in Iran in an effort to undermine internet censors in the country.

   2012 April 19, Josh Halliday, “Free speech haven or lawless cesspool – can the internet be civilised?”, in The Guardian, archived from the original on 08 May 2025

   When Morrison mulls the pluses and minuses associated with rebuking Kelly for undermining the government’s public health messaging, the prime minister faces a genuine substantive dilemma, and that goes to the risks of amplification.

   2021 February 2, Katharine Murphy, “Scott Morrison must heed the lesson of Donald Trump and slap down Craig Kelly”, in The Guardian, archived from the original on 27 Apr 2021

   The 'partygate' controversy has played a major part in undermining the credibility of Boris Johnson and his Government and has led to calls from senior MPs for him to resign.

   2022 January 26, “Network News: DfT awaits verdict on COVID 'partygate' scandal”, in RAIL, number 949, page 6

   Synonyms: corrode, undercut

3. To erode the base or foundation of something, e.g. by the action of water.

   Dungeness: The branch to the nuclear power station at Dungeness has been temporarily out of use because badgers have undermined the trackbed.

   2026 July 22, Howard Johnston, “Regional News: Southern”, in RAIL, number 1066, page 21

   1 more example

   Services between Glasgow Queen Street and Edinburgh Waverley via Falkirk High are currently suspended, following a 30-metre breach of the Union Canal that occurred on August 12 after torrential rain and thunderstorms. The thousands of gallons of water that cascaded onto the railway line below washed away track, ballast and overhead line equipment, and undermined embankments along a 300-metre section of Scotland's busiest rail link.

   2020 August 26, “Network News: Major flood damage severs key Edinburgh-Glasgow rail artery”, in Rail, page 21

4. human sciencesTo regard an object as the sum of the parts that compose it, in object-oriented ontology.

   We can even go further: when we consider an object in everyday life we do not usually just undermine or overmine it as if it demanded an either/or approach, but rather we run the two processes in tandem: duomining, as Harman labels it.

   2022, Nicholas Gayle, Conrad and the Being of the World, page 25