Definition of "undermine"

undermine

/ˌʌn.dəˈmaɪn/

verb
third-person singular simple present undermines, present participle undermining, simple past and past participle undermined
1. To dig underneath (something), to make a passage for destructive or military purposes; to sap.
  Quotations
  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. (figuratively) To weaken or work against; to hinder, sabotage.
  Quotations
  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
  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
3. To erode the base or foundation of something, e.g. by the action of water.
  Quotations
  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. (philosophy) To regard an object as the sum of the parts that compose it, in object-oriented ontology.
  Quotations
  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