(archaism, humorous) A person, such as a landlord, who receives or entertains guests.

(television) Host of an opinion show.

(Christianity) The sacrilegious mistreatment or malicious use of the host (consecrated bread of the Eucharist).

(ecology) The host in which a parasite reproduces sexually.

(biology) A living cell which harbours an infectious agent (such as a virus or bacterium).

plural of host cell

(geology) The background mineral material in which the object of study (crystals, fossils, specific minerals, groundwater, etc.) is embedded or through which it travels.

(Internet) A company offering bulletproof hosting.

(Internet) A web hosting service that allows customers to publish all kinds of material, including spam, pornography, etc. that may be forbidden on other services.

(computing) Synonym of jump server