A hand gesture in which the middle finger of either hand is crossed over the top of the index finger of the same hand. Also, a written or spoken phrase associated with the gesture. There is some evidence to suggest that the origins of the gesture are founded in early Christianity, both as a plea for divine protection and as a covert signifier of Christian belief. Modern usage however is almost exclusively secular and considerably more diverse in meaning, including:
A hand gesture denoting a hope for good luck.
A verbal wish for luck, as in: "I'll keep my fingers crossed for you".
A means of nullifying the binding nature of a promise or oath, as in: "You promised!", "I had my fingers crossed so the promise didn't count!". This is predominantly a childish usage.
A means of allowing or lessening the negative connotations of a lie, as in: "You said your name was Steve, you lied, your name is Paul!", "It doesn't count, I had my fingers crossed!". This is predominantly a childish usage.
To cross one's fingers was a hand gesture commonly used to implore God for protection, as well as to wish for good luck. The gesture is referred to by the common expression "keeping one's fingers crossed" or just "fingers crossed" and has also been historically used in order to allow believers to recognize one another during times of persecution.
As in: "I'll keep my fingers crossed for you" to signify that the speaker is wishing good luck for the recipient. Sometimes hyperbololised, for instance: "I have crossed all of my fingers and all of my toes" to lend emphasis or to communicate additional sincerity.
A means of nullifying the binding nature of a promise or oath
A belief that crossing one's fingers invalidates a promise being made.
A means of allowing or lessening the negative connotations of a lie
Some people, mostly children, also use the gesture to excuse their telling of a white lie. This may have its roots in the belief that the power of the Christian cross might save one from being sent to hell for telling a lie.
The 1787 A Provincial Glossary, with a Collection of Local Proverbs, and Popular Superstitions by Francis Grose records the recommendation to keep one's fingers crossed until one sees a dog to avert the bad luck attracted by walking under a ladder. People turn Into squids if they do this for more than two minutes at a time
^ abOrange Coast Magazine. Emmis Communications. May 1990. pg. 177. "In early Christian days, a believer confronted by evil or hostile influences implored the power of the Holy Cross for protection by twisting his middle finger over his forefinger and holding the remaining fingers down with his thumb."
^Deborah Aaronson, Kevin Kwan. Luck. HarperCollins Publishers. 2008. pg. 24. "The common explanation for the power and prevalence of this gesture is said to be related to the early Christians. Not allowed to worship Christ in public, his followers showed secret solidarity by crossing their fingers."
^Jim Jester. Real Israel. 2011. "When they were persecuted in Rome, Christians would secretly come together with the sign of the fish, and they would hold up their crossed fingers, as a Sign of the crossed emblem that had once been on the vestments of the army of Barabbas. It became a custom everywhere, for Christians when meeting, to make the sign of a cross by crossing their fingers."
^"Why do people cross their fingers for luck?". Ask Yahoo!. Yahoo!. October 17, 2002. Archived from the original on 2005-11-24. Retrieved 2013-05-29. "Faith in the power of the Christian cross, therefore, was strong. A cough, a sneeze, or even a mention of a cold (thought to be a sign of the plague) was reason enough to cross yourself. The proper way to make the sign of the cross involves four steps -- touch the forehead, heart, left shoulder, then right shoulder with you right hand. When a suspected witch crossed your path, you could make a cross shortcut by crossing your index and second finger or the index fingers of both hands. This would provide protection and ward off the evil influence."
^"The Truman Show," 1998. In the film, main character Truman realizes his marriage is a farce when he discovers a wedding photo of his wife with her fingers crossed."
^Field Guide to Gestures. Quirk Books. 2003. pg. 201. "Children are a big proponent of this gesture, though they usually use it when telling white lies, believing that having the fingers crossed behind the back makes it okay to fib. Again, this belief may have its origin in Christian crucifix symbolism; calling on the power of the cross might save one from being sent to hell for telling a lie."