web crawler

or web·crawl·er

noun Digital Technology.
  1. (sometimes initial capital letter) a computer program that retrieves data from a website, as in order to index web pages for a search engine.
Compare bot1.

Origin of web crawler

First recorded in 1990–95
Also called spider.
Related formsweb crawling, noun


  1. any of numerous predaceous arachnids of the order Araneae, most of which spin webs that serve as nests and as traps for prey.
  2. (loosely) any of various other arachnids resembling or suggesting these.
  3. any of various things resembling or suggesting a spider.
  4. a frying pan, originally one with legs or feet.
  5. a trivet or tripod, as for supporting a pot or pan on a hearth.
  6. Machinery.
    1. a part having a number of radiating spokes or arms, usually not connected at their outer ends.
    2. Also called cross.(in a universal joint) a crosslike part pivoted between the forked ends of two shafts to transmit motion between them.
  7. Also called web crawler. Digital Technology. a computer program that retrieves data from a website, as in order to index web pages for a search engine.
  8. an evil person who entraps or lures others by wiles.
  9. a device attached to a cultivator, for pulverizing the soil.
verb (used with object)
  1. Also crawl. Digital Technology. to retrieve (data) from a website using a computer program, as in order to index web pages for a search engine: Her company spiders the web for cheap flights and vacation deals.

Origin of spider

1300–50; Middle English spithre, Old English spīthra, akin to spinnan to spin; cognate with Danish spinder
Related formsspi·der·less, adjectivespi·der·like, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for web-crawler


  1. any predatory silk-producing arachnid of the order Araneae, having four pairs of legs and a rounded unsegmented body consisting of abdomen and cephalothoraxSee also wolf spider, trap-door spider, tarantula, black widow
  2. any of various similar or related arachnids
  3. a hub fitted with radiating spokes or arms that serve to transmit power or support a load
  4. agriculture an instrument used with a cultivator to pulverize soil
  5. any implement or tool having the shape of a spider
  6. nautical a metal frame fitted at the base of a mast to which halyards are tied when not in use
  7. any part of a machine having a number of radiating spokes, tines, or arms
  8. Also called: octopus British a cluster of elastic straps fastened at a central point and used to hold a load on a car rack, motorcycle, etc
  9. billiards snooker a rest having long legs, used to raise the cue above the level of the height of the ball
  10. angling an artificial fly tied with a hackle and no wings, perhaps originally thought to imitate a spider
  11. computing a computer program that is capable of performing sophisticated recursive searches on the internet
  12. short for spider phaeton

Word Origin for spider

Old English spīthra; related to Danish spinder, German Spinne; see spin
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for web-crawler



Old English spiþra, from Proto-Germanic *spenthro (cf. Danish spinder), from *spenwanan "to spin" (see spin). The connection with the root is more transparent in other Germanic cognates (cf. Middle Low German, Middle Dutch, Middle High German, German spinne, Dutch spin "spider").

In literature, often a figure of cunning, skill, and industry as well as poisonous predation. As the name for a type of two-pack solitaire, it is attested from 1890. Another Old English word for the creature was gangewifre "a weaver as he goes," and Middle English also had araine "spider" (14c.-15c., from French). Spider plant is from 1852; spider crab is from 1710; spider monkey is from 1764, so called for its long limbs.

Online Etymology Dictionary, © 2010 Douglas Harper

web-crawler in Medicine


  1. Any of numerous arachnids of the order Araneae, having a body divided into a cephalothorax bearing eight legs, two poison fangs, and two feelers and an unsegmented abdomen bearing several spinnerets that produce the silk used to make nests, cocoons, or webs for trapping insects.
  2. An arterial spider.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.