A phrase that combines a verb with a preposition or adverb or both and that functions as a verb whose meaning is different from the combined meanings of the individual words.
Phrasal Verb:
roll back [for something]
Meaning:
to return, rotating or turning or moving on wheels.
Example:
I rolled the ball away, thinking it would roll back. It didn't.
Phrasal verbs consists of a basic verb + another word or words. The two or three words that make up a phrasal verb form a short 'phrase' - which is why we call them 'phrasal verbs'.