List of Dictionaries & Glossaries vs Glossary Search Interfaces: Pros & Cons
Using known dictionaries & glossaries by going directly to their URL
pro: Your search will include any pages that are not indexed (therefore inaccessible) by any general-purpose search engine (Altavista, Google etc.).
con: You may not find your term and may need to open several glossaries before you do find it.
Using the glossary search interfaces and specifying your keyword/phrase
pro: The glossary that you find will contain your term (ideally as the term being defined; sometimes, however, as part of a definition of another term).
con: Your search is limited to those glossaries (and parts thereof) that are indexed by Altavista, Google etc.