• Acronym Finder   
  
  A searchable database containing common acronyms and abbreviations about a variety of subjects, with a focus on computers, technology, telecommunications, and the military. Look up over 379,000 acronyms and abbreviations.
  http://www.AcronymFinder.com/

• Acronyms and Common Terms Used in Material Safety Data Sheets
  
  http://www.cdc.gov/od/ohs/manual/chemical/chmsaf5.htm
• Acronyms and Initialisms for Health Information Resources
  
  Acronyms for global information and data resources in the health sciences.
  http://www.geocities.com/~mlshams/acronym/acr.htm
• Acronym Lookup
  
  Look up the meaning of an acronym or abbreviation.
  http://www.ucc.ie/cgi-bin/acronym/
• BioABACUS
  
  Biotechnology ABbreviation and ACronym Uncovering Service.
  http://www.nmsu.edu/~molbio/bioABACUShome.htm
• Chemical Compounds Abbreviations
  
  http://www.chemie.fu-berlin.de/cgi-bin/abbscomp
• EuroDicAutom
  
  European terminology database. Search for abbreviations and have the results returned in a variety of languages.
  http://europa.eu.int/eurodicautom/
• Explain Acronym Search
  
  Enter the acronym or abbreviation into this database and it will return its explanation.
  http://www.irs.aber.ac.uk/acronyms/
• Glossary for Healthcare Standards
  
  http://dmi-www.mc.duke.edu/dukemi/acronyms.htm
• Military Acronyms, Initialisms, and Abbreviations
  
  Want to know what the name of the military's F-15 jet is? Look it up here. Ironically, FUBAR is not listed.
  http://www.fas.org/news/reference/lexicon/acronym.htm
• Ocean Science-Related Acronyms
  
  From the Pacific Marine Environmental Laboratory (PMEL).
  http://acronyms.pmel.noaa.gov/
• Stands 4
  
  Over 300,000 acronyms and abbreviations to search from.
  http://www.stands4.com/
• U.S. Government Abbreviations and Acronyms
  
  Many of the meanings for the acronyms that the government uses such as FBI and DOJ, etc.
  http://www.ulib.iupui.edu/subjectareas/gov/docs_abbrev.html
• U.S. Postal Service Abbreviations
  
  Official abbreviations from the United States Postal Service.
  http://www.usps.gov/ncsc/lookups/abbrev.html

     See also, these cross-references:

• Almanacs and Facts
  
• Dictionaries
  
• Encyclopedias
  
• Famous and Familiar Quotations
  
• Thesaurus
  
• Translations