The meaning of UNDERMINE is to subvert or weaken insidiously or secretly. How to use undermine in a sentence. Synonym Discussion of Undermine.

UNDERMINE definition: 1. to make someone less confident, less powerful, or less likely to succeed, or to make something…. Learn more.

Some common synonyms of undermine are cripple, debilitate, disable, enfeeble, sap, and weaken. While all these words mean "to lose or cause to lose strength or vigor," undermine and sap suggest a weakening by something working surreptitiously and insidiously.

undermine something/somebody to make something, especially somebody’s confidence or authority, gradually weaker or less effective. Our confidence in the team has been seriously undermined by their recent defeats. This crisis has undermined his position. Recent changes have undermined teachers’ morale.

To undermine literally means to dig a hole underneath something, making it likely to collapse. But we more often use the word to describe sabotage or the act of weakening someone else's efforts.

If you undermine something such as a feeling or a system, you make it less strong or less secure than it was before, often by a gradual process or by repeated efforts.

If you undermine something such as a feeling or a system, you make it less strong or less secure than it was before, often by a gradual process or by repeated efforts.

If you undermine something such as a feeling or a system, you make it less strong or less secure than it was before, often by a gradual process or by repeated efforts.

1. to impair, weaken, or destroy (health, morale, etc.) by imperceptible stages. 2. to make an excavation under; dig or tunnel beneath. 3. to weaken or cause to collapse by removing underlying supports. un′der•min`er, n. Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc.

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 …