A phrase that consists of a verb with a preposition or adverb or both, the meaning of which is different from the meaning of its separate parts.
Phrasal Verb:
knock something out
Meaning / Example:
1. to create something hastily. > He knocked a few out as samples. > He knocked out a few of them quickly, just so we could see what they were going to look like.
2. to put something out of order; to make something inoperable. > The storm knocked the telephone system out.
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.