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:
fill something out Fig.
Meaning:
to complete a form by writing in the blank spaces.
Example:
Please fill this form out and send it back to us in the mail.
Phrasal verbs, also called two-word verbs, are idiomatic expressions wherein the second element of the verb (the adverb or particle) is not necessarily predictable.