In the internet term “WWWW”, what does the 4th “W” stand for?

The Full form of WWWW is World Wide Web Worm.

The World Wide Web Worm (WWWW) was one of the earliest search engines for the World Wide Web (WWW). It is claimed by some to be the first search engine, though it was not released until March 1994, by which time a number of other search engines had been made publicly available. It was developed in September 1993 by Oliver McBryan at the University of Colorado as a research project.

This worm created a database of 300,000 multimedia objects which can be obtained when someone searched for keywords via the www. The wwww featured support for Perl regular expressions in contrast to search engines nowadays.

Additional Information:

World-wide web worm can be used for publicity, marketing and advertising, direct online selling, research and development, communication purposes, collaboration, industrial classification and multimedia. It is one of the first indexing programs. The world wide web worm is sometimes confused with the internet worm which was a virus unleashed into the internet in the late 1980s.