Simple Definition:

A phrasal verb is a combination of a verb and one or more particles (small words such as “off”, “up”, and “on”) that together have a different meaning than the individual words. Phrasal verbs are commonly used in English to express various actions and ideas.

Examples:

1. She called off the meeting. (“called off” is a phrasal verb meaning cancel)
2. He ran into his old friend at the supermarket. (“run into” is a phrasal verb meaning meet unexpectedly)

Very Simple Definition:

A phrasal verb is a combination of words that together mean something different than the words separately.

Examples:

1. She got up late. (woke up)
2. He ran out of pencils. (used all of his pencils)