[ uhn-der-mahyn or, especially for 1, 2, 4, uhn-der-mahyn ]
See synonyms for: undermineunderminedunderminesundermining on Thesaurus.com

verb (used with object),un·der·mined, un·der·min·ing.
  1. to injure or destroy by insidious activity or imperceptible stages, sometimes tending toward a sudden dramatic effect.

  2. to attack by indirect, secret, or underhand means; attempt to subvert by stealth.

  1. to make an excavation under; dig or tunnel beneath, as a military stronghold.

  2. to weaken or cause to collapse by removing underlying support, as by digging away or eroding the foundation.

Origin of undermine

First recorded in 1300–50; Middle English underminen; see under-, mine2

Other words from undermine

  • un·der·min·er, noun

Words Nearby undermine

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use undermine in a sentence

British Dictionary definitions for undermine


/ (ˌʌndəˈmaɪn) /

  1. (of the sea, wind, etc) to wear away the bottom or base of (land, cliffs, etc)

  2. to weaken gradually or insidiously: their insults undermined her confidence

  1. to tunnel or dig beneath

Derived forms of undermine

  • underminer, noun

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012