Exoparasitism

Part of speech: noun

Definitions

1. The way of life in which an organism lives on the external surface of a host, feeding on it without living inside its body
2. A relationship in which a parasite attaches to and draws nourishment from the outside of another living creature
3. Dependence on a host by residing on its exterior, as seen in lice, ticks and fleas that feed on skin or fur

Etymology: Exoparasitism is a formal biological term, built in the modern scientific manner from classical parts. The prefix "exo-" comes from Greek "exō", meaning "outside", and "parasitism" traces back to Greek "parasitos", literally "one who eats beside another", from "para" (beside) and "sitos" (food or grain). The Greek sense of a parasite was originally a social figure, a guest or hanger-on who dined at another's table, and only later a term for a freeloader or a creature living on a host. The pairing of "exo-" with "parasitism" to name living on the outside of a host, as opposed to inside it, is a later scientific construction. Such compounds were coined in the 19th and 20th centuries when zoologists and parasitologists needed precise vocabulary to distinguish ectoparasites (on the surface of a host, like fleas and ticks) from endoparasites (within the body). The Greeks never used the word itself, which postdates them by two millennia. The noun "exoparasitism" therefore names a state of living, not a single organism, and the classical parts were simply reassembled to describe it.

Antonyms: endoparasitism