an animal or plant that lives in or on a host (another animal or plant); it obtains nourishment from the host without benefiting or killing the host
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a follower who hangs around a host (without benefit to the host) in hope of gain or advantage
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Parasite \Par"a*site\ (p[a^]r"[.a]*s[imac]t), n. [F., fr. L. parasitus, Gr. para`sitos, lit., eating beside, or at the table of, another; para` beside + sitei^n to feed, from sitos wheat, grain, food.] 1. One who frequents the tables of the rich, or who lives at another's expense, and earns his welcome by flattery; a hanger-on; a toady; a sycophant.
Thou, with trembling fear, Or like a fawning parasite, obey'st. --Milton.
Parasites were called such smell-feasts as would seek to be free guests at rich men's tables. --Udall.
2. (Bot.) (a) A plant obtaining nourishment immediately from other plants to which it attaches itself, and whose juices it absorbs; -- sometimes, but erroneously, called epiphyte. (b) A plant living on or within an animal, and supported at its expense, as many species of fungi of the genus {Torrubia}.
3. (Zo["o]l.) (a) An animal which lives during the whole or part of its existence on or in the body of some other animal, feeding upon its food, blood, or tissues, as lice, tapeworms, etc. (b) An animal which steals the food of another, as the parasitic jager. (c) An animal which habitually uses the nest of another, as the cowbird and the European cuckoo.
"The fresh-water amoeba that people play with is harmless," said Loew, a University of Connecticut Health Center physiologist. "But one form is a parasite that lives in people and causes amoebic dysentery.
The guinea worm is a debilitating parasite that thrives in impure water and affects people in rural areas of Africa and Asia.
The parasite is highly resistant to chlorine, which kills other germs.
Suramin, a drug long used to treat parasite infections, is being tested for the first time as a way to attack cancer.
Scientists reported encouraging results today in the first human tests of an experimental vaccine that fights a malaria-causing parasite at the stage when it infects red blood cells.
The journalist, Sergei I. Grigoryants, whom Gorbachev condemned in a May interview as a "parasite" "sponging on the democratic process," managed to elude officers for a few minutes.
"Doru Pavaloaie does not have a job and lives like a parasite. Since the very beginning of the marriage both of them have wanted to leave the country and go to Germany to his wife's relatives," he wrote at a safehouse known only by the codename Rosa.
Three of the five volunteers who got one protein had mild infections, but with a steady decrease in parasite counts and total recovery by three weeks.
Spores of the parasite are put on wheat bran flakes to form a bait.
One died after being attacked by a coyote, another died of the brainworm parasite, and three others died of stress and reaction to a drug.
The Varroa mite is an external parasite of adult bees and their developing larvae.
Scientists reported today that red blood cells infected with a malaria-causing parasite stick to the protein, which is found in the inner lining of blood vessels.
The disease, which destroys vital red blood cells, is caused by a parasite called Plasmodium.
A bottlenose dolphin that died after swimming up the East and Hudson rivers was infected by a parasite that apparently affected its sense of direction, an autopsy revealed.
The screwworm fly is a flesh-eating parasite that attacks all warm-blooded animals, even humans, and is a serious threat to livestock.