parasitize

Parasitize is a verb that describes the action of obtaining benefits by living on or in a host organism, from which the parasite derives resources such as nutrients or shelter, typically to the detriment of the host. In biology, a parasite is an organism that lives in or on another organism (the host) and relies on it for survival, growth, or reproduction. Parasites range from microscopic organisms to larger plants and animals, and parasitism represents a type of symbiotic relationship distinct from mutualism and commensalism.

Parasites can be classified by their location relative to the host: endoparasites live inside the host’s body; ectoparasites live on the surface. They can be obligate, requiring a host to complete their life cycle, or facultative, able to exploit a host opportunistically. Host ranges vary from highly specific to broad. Transmission can occur through vectors, consumption of infected material, direct contact, or environmental stages. Parasites often have complex life cycles that may involve multiple hosts and stages, and they typically evolve strategies to evade the host’s immune defenses to prolong reproduction and transmission.

Common examples include protozoans such as Plasmodium (which causes malaria); helminths such as tapeworms and nematodes; and ectoparasites such as fleas, ticks, and lice. Parasitic plants, such as mistletoe, derive water and nutrients from host plants. The study of parasitism covers host-parasite interactions, life cycles, transmission dynamics, and the evolutionary arms race between parasites and hosts.

Outside biology, parasitize is used metaphorically to describe exploitation of systems, resources, or individuals by taking unfair advantage or leveraging vulnerability.