Search Engine Glossaries
Essential Search Engine Lingo
http://www.searchenginedictionary.com/p.shtml
Personal Favorite of BB Media, it covers both Search Engine Optimzitiona and Search Engine Marketing Terms. A comprehensive guide to search engine terminology - from Pandecta Magazine.
Search Engine Glossary
http://searchenginewatch.com/facts/glossary.html
This glossary from Search Engine Watch provides is a basic overview of terminology. It's a good place to start if you're unfamiliar with search engine terms and concepts, written in a relatively non-technical format.
Search Engine Showdown Glossary
http://www.searchengineshowdown.com/glossary.html
More advanced definitions of search engine terms from search guru Greg Notess, designed to illuminate the in-depth reviews, evaluations and articles about the technology featured on the Search Engine Showdown site.
Glossary of Internet & Web Jargon
http://www.lib.berkeley.edu/TeachingLib/Guides/Internet/Glossary.html
This glossary from the U.C. Berkeley Teaching Library includes definitions for web and net terminology searchers invariably encounter while surfing the web. Helpful for getting a much broader understanding
More Technically Oriented Search Engine Glossaries
Search Engine Terms
http://www.cadenza.org/search_engine_terms/
This glossary was created by and for the members of the I-Search discussion list, geared toward webmasters and search engine marketing specialists who want to understanding how to get higher listings in search engine rankings. It's a multi-lingual glossary, available in six European languages other than English.
Search Terms Glossary
http://www.searchtools.com/info/glossary.html
This glossary is a companion to the Search Tools web site, which focuses more on the world of local web site search technology rather than the global web search engines. It offers detailed definitions that are often cross-linked to each other, with abundant examples that illustrate key concepts.
Modern Information Retrieval Glossary
http://www.sims.berkeley.edu/%7Ehearst/irbook/glossary.html
This glossary is from the textbook "Modern Information Retrieval" by Ricardo Baeza-Yates and Berthier Ribeiro-Neto. It's comprehensive, but highly academically oriented, though offering the additional bonus of links to other companion resources for the textbook.