Verb

(undermin)

To dig underneath (something), to make a passage or for destructive or military purposes; to sap.

* 2009 , (Diarmaid MacCulloch), A History of Christianity , Penguin 2010, p. 312:

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.

(figuratively) To weaken or work against; to hinder, sabotage.

* {{quote-news, year=2012, date=April 19, author=Josh Halliday, work=the Guardian

, title= Free speech haven or lawless cesspool – can the internet be civilised? , passage=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.}}

Verb

(en-verb)

To renounce or dissolve all bonds of affiance, faith, or obligation with; to reject, refuse, or renounce.

* 1603-1625 , (Beaumont and Fletcher)

For thee I have defied my constant mistress.

To challenge (someone) to do something difficult.

* 1671 , (John Milton), (Samson Agonistes)

I once again / Defie thee to the trial of mortal fight.

* 1900 , Edith King Hall, Adventures in Toyland Chapter 6

*:"So you actually think yours is good-looking?" sneered the Baker. "Why, I could make a better-looking one out of a piece of dough."

*:"I defy you to," the Hansom-driver replied. "A face like mine is not easily copied. Nor am I the only person of that opinion. All the ladies think that I am beautiful. And of course I go by what they think."

To refuse to obey.

* 2005 , , Presidential Radio Address - 19 March 2005

*:Before coalition forces arrived, Iraq was ruled by a dictatorship that murdered its own citizens, threatened its neighbors, and defied the world.

*{{quote-magazine, date=2013-08-10, volume=408, issue=8848, magazine=(The Economist), author=Lexington

, title= Keeping the mighty honest , passage=British journalists shun complete respectability, feeling a duty to be ready to savage the mighty, or rummage through their bins. Elsewhere in Europe, government contracts and subsidies ensure that press barons will only defy the mighty so far.}}

To not conform to or follow a pattern or certain set of rules.

* 1955 , Anonymous, The Urantia Book Paper 41

*:By tossing this nineteenth electron back and forth between its own orbit and that of its lost companion more than twenty-five thousand times a second, a mutilated stone atom is able partially to defy gravity and thus successfully to ride the emerging streams of light and energy, the sunbeams, to liberty and adventure.

* 2013 , Jeré Longman in the New York Times, W.N.B.A. Hopes Griner Can Change Perceptions, as Well as Game Itself

*:“To be determined,” Kane said, “is whether Griner and her towering skill and engaging personality will defy the odds and attract corporate sponsors as part of widespread public acceptance four decades after passage of the gender-equity legislation known as Title IX.”