cross one's fingers
to cross two fingers of one hand to hope or wish for good luck

[TahlilGaran] Dictionary of Contemporary English ▲

cross fingers
cross (your) fingers
to hope for good luck.
At this point, they can only stand back, cross their fingers and wait to see if the fireworks go off perfectly.

Etymology: based on the practice, esp. of children, to put one finger over the next one either as a sign of hope for good luck or to avoid punishment

[TahlilGaran] English Idioms Dictionary ▲

cross one's fingers
to cross two fingers of one hand to hope or wish for good luck
I crossed my fingers that I would get the job that I had applied for.

[TahlilGaran] English Idioms Dictionary ▲

cross one's fingers
v. phr.
1a. To cross two fingers of one hand for good luck.
Mary crossed her fingers during the race so that Tom would win.
11b. or keep one's fingers crossed informal To wish for good luck.
Keep your fingers crossed while I take the test.
2. To cross two fingers of one hand to excuse an untruth that you are telling.
Johnny crossed his fingers when he told his mother the lie.

[TahlilGaran] English Idioms Dictionary ▲