host

To receive and entertain guests, or to organise and present an event.

"London will host the next major conference."

A person who receives and entertains guests, or presents an event.

"She was the perfect host for the evening."

An animal or plant that provides nourishment and shelter for a parasite.

"Mosquitoes can be a host for malaria."

A very large number or quantity of people or things.

"A host of problems complicated the project."