If the suffix-ism means practice of how would you define parasitism?

While "-ism" often denotes a practice, it's not always the case. In the context of "parasitism," it refers to a relationship rather than a practice.

Here's a breakdown:

* Parasite: An organism that lives in or on another organism (the host) and benefits by deriving nutrients at the host's expense.

* Parasitism: The biological relationship between two organisms where one (the parasite) benefits at the expense of the other (the host).

Therefore, parasitism is not the practice of being a parasite but rather the nature of the relationship between the parasite and the host.