parasite

parasite

an animal or plant that lives in or on another (the host) from which it obtains nourishment. The host does not benefit from the association and is often harmed by it

Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

parasite

[′par·ə‚sīt]

(biology)

An organism that lives in or on another organism of different species from which it derives nutrients and shelter.

(electricity)

Current in a circuit, due to some unintentional cause, such as inequalities of temperature or of composition; particularly troublesome in electrical measurements.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

parasite

Unsolicited software that is installed in a computer without users realizing it. There are many different types. Parasites can report Web browsing habits to a marketing company over the Internet (see spyware) or change browser settings to point to a specific site. They can redirect search engine results to a site that sells a related product, and they can cause premium services to be dialed up.

Read the License Agreement
Parasites are often installed with freeware, and the license agreement may actually say so, but hardly anyone reads it. Sometimes, users can opt out of installing the parasite and install only what they wanted in the first place. Be sure security settings are set to medium at least, and never click "Yes" to any dialog that asks "do you want to run" or "execute" something unless you know what that something is. ActiveX controls on the Web cannot only install parasites but viruses as well.

Parasites often do not include an uninstall function and may not be easily removed, although anti-parasite programs can detect and remove them (see spyware blocker).

Copyright © 1981-2025 by The Computer Language Company Inc. All Rights reserved. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction is strictly prohibited without permission from the publisher.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Parasite

 

an organism that feeds on and usually harms another organism, which is called the host. A distinction is made between zooparasites, including protozoans, helminths, arachnids, and insects, and phytoparasites, including bacteria, fungi, and some higher plants. Viruses are also classified as parasites.

Parasites are found in all taxonomic groups except echinoderms, brachiopods, most chordates, mosses, ferns, and gymnosperms. Bacteria, actinomycetes, plants, and animals of all taxonomic groups may serve as hosts. Parasites weaken and exhaust the host and often kill it. Some parasites require a succession of two or three hosts on which to complete their life cycle.

Parasites arose in the course of evolution from free-living forms. In adapting to their new living conditions, their internal organization was simplified, and they acquired special organs for attachment, in addition to well-developed sex organs. Anaerobic respiration enables parasites to exist in environments that lack oxygen. Many parasites cause diseases of man, animals, and plants.

B. E. BYKHOVSKII

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.