* * *
1. An organism that lives on or in another and draws its nourishment therefrom. 2. In the case of a fetal inclusion or conjoined twins, the usually incomplete twin that derives its support from the more nearly normal autosite. [G. parasitos, a guest, fr. para, beside, + sitos, food]
- accidental p. SYN: incidental p..
- autochthonous p. SYN: autistic p..
- facultative p. an organism that may either lead an independent existence or live as a p., in contrast to obligate p..
- obligate p. a p. that cannot lead an independent nonparasitic existence, in contrast to facultative p..
- quartan p. SYN: Plasmodium malariae.
- specific p. a p. that habitually lives in its present host and is particularly adapted for the host species.
- spurious p. organisms that parasitize other hosts that pass through the human intestine and are detected in the stool after ingestion ( e.g., Capillaria sp. eggs in animal liver).
- tertian p. SYN: Plasmodium vivax.
* * *
par·a·site 'par-ə-.sīt n an organism living in, with, or on another organism in parasitism
* * *
n.
any living thing that lives in (see endoparasite) or on (see ectoparasite) another living organism (see host). The parasite, which may spend all or only part of its existence with the host, obtains food and/or shelter from the host and contributes nothing to its welfare. Some parasites cause irritation and interfere with bodily functions; others destroy host tissues and release toxins into the body, thus injuring health and causing disease. Human parasites include fungi, bacteria, viruses, protozoa, and worms. See also commensal, symbiosis.
• parasitic adj.
* * *
par·a·site (parґə-sīt) [Gr. parasitos] 1. a plant or animal that lives upon or within another living organism at whose expense it obtains some advantage. See symbiosis. 2. the smaller, less complete component of asymmetrical conjoined twins, which is attached to and dependent on the autosite.Medical dictionary. 2011.