1. A person who receives or entertains guests at home or elsewhere: the host at a theater party.
2. A master of ceremonies, moderator, or interviewer for a television or radio program.
3. A person, place, company, or the like, that provides services, resources, etc., as for a convention or sporting event: Our city would like to serve as host for the next Winter Olympics.
4. The landlord of an inn.
5. A living animal or plant from which a parasite obtains nutrition.