Final answer:
The term 'host' refers to the organism being harmed by a parasite, which benefits from the relationship by deriving nutrients at the host's expense.
Step-by-step explanation:
The term that refers to the partner being harmed by a parasite is the host. A parasite is an organism that lives in or on another living organism, called the host, and derives nutrients from it. In this relationship, the parasite benefits by obtaining resources such as nutrients, while the host is harmed, often experiencing a reduction in fitness or health. On the other hand, a vector is an organism that carries pathogens from one host to another without being infected itself, such as mosquitoes carrying malaria parasites. A carrier is an individual that harbors a pathogen without showing symptoms and can spread it to others, while a reservoir is an organism or environment where the pathogen can be maintained before infecting a new host.