1. The act of suspending someone from an institution or activity on a temporary or permanent basis as a result of bad or poor conduct: Larry’s parents were very upset when they received notice that their son's bad behavior towards his classmates in school resulted in his expulsion for a week from the school.
2. An occasion of officially forcing a person to leave a nation, mainly because of breaking the rules and regulations or for political reasons: Ted's country decided on the expulsion of the diplomats after having severe issues with their governments.
3. The procedure of forcefully pushing something out of the body or out of a container: Jack was very sick and after the expulsion of the contents of his stomach, he felt much better.

Maxine had too many old messages in her e-mail server which were overloading it; so, she spent a great deal of time making expulsions which made it possible for her computer to function more efficiently.