cross (one's) fingers

cross (one's) fingers

To hope for good luck or that something will happen. The actual gesture, which does not have to accompany the phrase, involves crossing one's middle finger over the index finger as a superstitious belief that it will bring good luck. I'm crossing my fingers that I get a bike for my birthday! Cross your fingers that this is the news we've been waiting for.
See also: cross, finger
Farlex Dictionary of Idioms.

cross one's fingers

Also, keep one's fingers crossed.
1. Wish for luck by crossing two fingers of one hand. For example, I'm crossing my fingers that I get the job, or Keep your fingers crossed that the hurricane goes out to sea. This superstitious statement presumably alludes to the much older practice of making the sign of the cross to ward off evil. [Early 1900s]
2. Tell a white lie that doesn't matter. For example, I told Mom I didn't eat any cookies but I had my fingers crossed. The childish belief that if one keeps one's fingers crossed one may lie with impunity probably comes from children's games in which one was "safe" if one crossed one's fingers, and the ultimate allusion may be the same as in def. 1.
See also: cross, finger
The American Heritage® Dictionary of Idioms by Christine Ammer.
See also:
  • cross one's fingers
  • cross your fingers
  • keep (one's) fingers crossed
  • keep fingers crossed
  • keep your fingers crossed
  • have (one's) fingers crossed
  • have/keep your fingers crossed
  • tag along after (someone)
  • tag along behind (someone)
  • come with