Keep one’s fingers crossed

What is Keep one’s fingers crossed?

Keep one’s fingers crossed definition and meaning on Dictionary terms:
any of the terminal members of the hand, especially one other than the thumb.
a part of a glove made to receive a finger.

the breadth of a finger as a unit of measurement; digit.
the length of a finger: approximately 4A? inches (11 cm).
Slang. an informer or spy.
something like a finger in form or use, as a projection or pointer: a finger of land leading out into the bay; the finger on the speedometer.
any of various projecting parts of machines.

verb (used with object)
to touch with the fingers; toy or meddle with; handle.
to touch with the fingers so as to mar or spoil: Please don’t finger the vegetables.

to pilfer; filch.
Music. to play on (an instrument) with the fingers. to perform or mark (a passage of music) with a certain fingering.

Slang. to inform against or identify (a criminal) to the authorities: He fingered the man who robbed the bank. to designate as a victim, as of murder or other crime.

verb (used without object)
to touch or handle something with the fingers.
to extend in or as in the shape of a finger: Landing piers finger out into the river along the city’s shoreline.