The phrase is a meaningful group of words without a subject and a predicate. It is a group of words without a verb except for the verb phrase that has a verb as its headword. The phrase is an integral part of a sentence that does not have a complete meaning on its own.
A phrase is made up of a headword and its modifiers. It takes its name from the headword, which is the type of words it contains. In essence, the headword of the noun phrase is a noun.