parasitic (adj.)

"of pertaining to, or characteristic of a parasite," in any sense, 1620s, from Latin parasiticus, from Greek parasitikos "of or pertaining to a parasite; the trade of a parasite," from parasitos "one who lives at another's expense" (see parasite). Biological sense is from 1731. Related: Parasitical, 1570s in reference to toadies; from 1640s in the biological sense.