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.
Phrasal Verb:
fight someone or something down
Meaning:
to fight against and defeat someone or something.
Example:
We fought the opposition down and got our bill through the committee.
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