1. Of the nature of a parasite; fawning for food or favors; sycophantic: Lynn_s neighbors seemed to be quite parasitical because they often asked for help or some food they had forgotten to buy, but they always said "no" when Lynn wanted some help from them.
2. Of or pertaining to parasites; living on, or deriving nourishment from, some other living animal or plant: Mary was diagnosed with parasitical worms which she evidently aquired while she was on a camping trip in Italy.