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.
stake a claim to (something)
to make a claim for something
Everybody in our class tried to stake a claim to the free cell phones.
List of common idioms, their meanings and examples of their usage in sentences
Idioms are phrases which cannot be understood simply by looking at the meaning of the individual words in the phrase.