Phrasal verbs are two-word phrases, either as VERB + PREPOSITION or VERB + ADVERB.
For example: run into, check in, cheer up, get up, hang out, shut off
Each of these phrasal verbs have a meaning that is different from the individual words its made up of. This means the phrasal verb "cheer up" means something different than the words "cheer" and "up."
"Call off" is another example of a phrasal verb. We hear this quite often in a variety of settings, both formal and informal so it's quite useful to know.
So what does it mean?
You can see these examples below.