undermine

[ uhn-der-mahyn or, especially for 1, 2, 4, uhn-der-mahyn ]
/ ˌʌn dərˈmaɪn or, especially for 1, 2, 4, ˈʌn dərˌmaɪn /

verb (used with object), un·der·mined, un·der·min·ing.

to injure or destroy by insidious activity or imperceptible stages, sometimes tending toward a sudden dramatic effect.
to attack by indirect, secret, or underhand means; attempt to subvert by stealth.
to make an excavation under; dig or tunnel beneath, as a military stronghold.
to weaken or cause to collapse by removing underlying support, as by digging away or eroding the foundation.

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Origin of undermine

First recorded in 1300–50, undermine is from the Middle English word underminen.See under-, mine2

OTHER WORDS FROM undermine

un·der·min·er, nounun·der·min·ing·ly, adverb
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for undermine

British Dictionary definitions for undermine

undermine
/ (ˌʌndəˈmaɪn) /

verb (tr)

(of the sea, wind, etc) to wear away the bottom or base of (land, cliffs, etc)
to weaken gradually or insidiouslytheir insults undermined her confidence
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