In grammar, a phrase—called an expression in some contexts—is a group of one or more words acting as a grammatical unit. For instance, the English expression "the very happy squirrel" is a noun phrase which contains the adjective phrase "very happy". Phrases can consist of a single word or a complete sentence. In theoretical linguistics, phrases are often analyzed as units of syntactic structure such as a constituent. There is a difference between the common use of the term phrase and its technical use in linguistics. In common usage, a phrase is usually a group of words with some special idiomatic meaning or other significance, such as "all rights reserved", "economical with the truth", or "kick the bucket". It may be a euphemism, a saying or proverb, a fixed expression, a figure of speech, etc. In linguistics, these are known as phrasemes. In theories of syntax, a phrase is any group of words, or sometimes a single word, which plays a particular role within the syntactic structure of a sentence. It does not have to have any special meaning or significance, or even exist anywhere outside of the sentence being analyzed, but it must function there as a complete grammatical unit. For example, in the sentence Yesterday I saw an orange bird with a white neck, the words an orange bird with a white neck form a noun phrase, or a determiner phrase in some theories, which functions as the object of the sentence. Source: Wikipedia (en)