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:
bet on the wrong horse
Meaning:
to misjudge a coming event, to misread the future
Example:
I think that my uncle bet on the wrong horse by investing all of his money in the new stock.
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.