An expression in the usage of a language that is peculiar to itself either in having a meaning that cannot be derived from the conjoined meanings of its elements or in its grammatically atypical use of words.
Idiom:
get into the wrong hands
Meaning:
something secret or dangerous is discovered by someone who should not have it
Example:
The teacher was careful that the test answers did not get into the wrong hands.
List of common idioms, their meanings and examples of their usage in sentences
An idiom is a group of words, or in other words, a phrase that has a meaning different from the literal meaning of the words in it.