Parasitical (adjective)

Related to or characteristic of a parasite; living off or at the expense of another.

Origin:

Parasite + -ical.

Examples:

1. The plant was killed by the parasitical fungus.
2. The relationship between the host and the parasite is often harmful to the host.
3. The parasitical relationship between the two species was studied by the scientists.
4. The employee's behavior was seen as parasitical as he only worked when someone else was present.
5. The company's success was built on parasitical relationships with other firms.