3. (Genetics) An organism bearing certain genetic material. (wiktionary.org)
5. An area in which particular living things are found. (Google Dictionary)
6. A living cell in which a virus multiplies. (Google Dictionary)
7. A person whose immune system has been invaded by a pathogenic organism. (Google Dictionary)
9. An animal or plant that nourishes and supports a parasite; it does not benefit and is often harmed by the association) (wordnetweb.princeton.edu)
10. (Medicine) Recipient of transplanted tissue or organ from a donor). (wordnetweb.princeton.edu)
Word origin: From Old French hoste “guest, host, hostess, landlord” (12c., Modern French hôte), from Latin hospitem (nominative hospes) “guest, host,” literally “lord of strangers,” from PIE *ghostis- “stranger” (cf. Old Church Slavonic gosti “guest, friend,” gospodi “lord, master”).