Answer:
Phrase, Idiom or Sentence
Step-by-step explanation:
A sequence of words that form a meaning can be a phrase, idiom or a sentence.
A phrase is a group of words that form a meaning. It can be a combination of a preposition and a noun, or an adjective and a noun. Prepositional phrase is for example "in the air", and an adjectival phrase is "a beautiful girl".
An idiom is a phrase that when formed, changes the meaning of the words in a phrase. For example, "It's raining cats and dogs". This sentence doesn't mean that literally cats and dogs fall from the sky, but it has a different meaning, which is "It is heavily raining."
A sentence is a group of words that must consist of at least subject and a verb, which can be followed by other words or phrases. For example, a phrase is "a beautiful girl" - it cannot be a sentence because it doesn't have a verb. If we say "A beautiful girl is here." - we make a sentence, because now it has a subject (A beautiful girl), a verb (is) and a preposition of place (here).