[uhn-der-mahyn or especially for 1, 2, 4, uhn-der-mahyn]
verb (used with object), undermined, undermining.
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.

1300–50; Middle English underminen. See under-, mine2

underminer, noun
underminingly, adverb
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source Link To undermines
World English Dictionary
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
3.  to tunnel or dig beneath

Collins English Dictionary - Complete & Unabridged 10th Edition
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
Cite This Source
Word Origin & History

c.1300, undermyne, from under + mine (v.). The fig. sense is attested from c.1430. Cf. Du. ondermijnen, Dan. underminere, Ger. unterminiren.
Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
Example sentences
Acting with callous disregard for the feelings of other animals undermines our
  empathic natures and humane sensitivities.
Perhaps because it undermines our human ego to realise otherwise.
Too bad the fall time was extended and thus for a few weeks, undermines this
  reasonable effort.
Good news, even qualified good news, runs counter to the conventional wisdom
  and undermines almost everybody's agenda of reform.
Related Words
Copyright © 2014 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature