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n 1: someone who races the luge [syn: {luger}]

2: freshwater turtle of United States and South America;

frequently raised commercially; some young sold as pets

[syn: {yellow-bellied terrapin}, {Pseudemys scripta}]

3: a fastball that curves slightly away from the side from

which it was thrown

spider

(Or "robot", "crawler") A program that

automatically explores the {World-Wide Web} by retrieving a

document and recursively retrieving some or all the documents

that are referenced in it. This is in contrast with a normal

{web browser} operated by a human that doesn't automatically

follow links other than {inline images} and {URL redirection}.

The algorithm used to pick which references to follow strongly

depends on the program's purpose. {Index}-building spiders

usually retrieve a significant proportion of the references.

The other extreme is spiders that try to validate the

references in a set of documents; these usually do not

retrieve any of the links apart from redirections.

The {standard for robot exclusion} is designed to avoid some

problems with spiders.

Early examples are {Lycos}, {WebCrawler}, and {Yahoo!}.

{Home

(http://info.webcrawler.com/mak/projects/robots/robots.html)}.

(1999-08-26)