The word "parasitize" has a lot of different meanings, and as such, there are many different synonyms that can be used to describe it. Some of the most common synonyms include "leeching," "feeding off of," "exploiting," "preying on," and "sponging off of." These words all imply some kind of negative or parasitic relationship between two things. Other synonyms for "parasitize" might include "draining," "burdening," "mooching," "taking advantage of," or "living off of." Ultimately, the choice of synonym depends on the context in which the word is being used and the specific connotations that the writer wants to convey.