Definition of "loophole"

[…] and having a fair loophole, as it were, from a broken hole in the tree, he took a sure aim, without being seen, waiting till they were within about thirty yards of the tree, so that he could not miss.

1719 May 6 (Gregorian calendar), [Daniel Defoe], The Life and Strange Surprizing Adventures of Robinson Crusoe, […], 3rd edition, London: […] W[illiam] Taylor […], published 1719

There was a loophole in this wall, to let the light in, just at the height of a person's head, who was sitting near the chimney.

1809, Maria Edgeworth, The Absentee

The sun had shifted round, and the myriad windows of the Ministry of Truth, with the light no longer shining on them, looked grim as the loopholes of a fortress.

1949, George Orwell, Nineteen Eighty-Four, page 25

Coupling the poor girl's intelligence with my previous knowledge, and the result of our good friend's inquiries on the spot, I left him no loophole of escape, and laid bare the whole villany which by these lights became plain as day.

1838, Charles Dickens, chapter 49, in Oliver Twist, page 236

You have a contract that says you will work until Island Towers is finalized, which I interpret as completion of construction, or I can stop you working elsewhere. And there's no loopholes, because you drafted it and you're the best.

2002, Marc Lawrence, Two Weeks Notice (motion picture)

They would rather ask more from the vast majority of Americans and put our recovery at risk than close even a single tax loophole that benefits the wealthy.

2013 February 9, Barack Obama, The Support They Need

The lower windows were barricaded, and the whole building loopholed for musketry fire.

1896, Arthur Conan Doyle, The Exploits Of Brigadier Gerard‎

The doors were barricaded, the shutters closed upon the windows and loopholed, and provisions were brought in from the outhouses.

1907, A. E. W. Mason, The Broken Road‎

The Germans were loopholing it for defence.

1915, W. H. L. Watson, Adventures of a Despatch Rider‎

Abroad they had developed loopholing the law into an art; in Israel they jettisoned loopholing for ignoring the law wherever possible. Obeying laws was for naive fools.

1988, Macabee Dean, The Ashmadai Solution: A Surrealistic Extrapolation of a Gentle Genocide

De-moralizing the subject can be, quite simply, demoralizing, as stirring statements of ideals turn into persnickety rules with exceptions crying out to be loopholed.

2005, Deborah Rhode, David Luban, Legal Ethics Stories