Definitions & Abbreviations

This medical dictionary with the trusted name of Merriam-Webster provides the user with a pronunciation guide, explanatory notes, and an advanced search page.

MediLexicon has "the largest online database of pharmaceutical and medical abbreviations" in the world.  The database is free to use and updated daily.

The Drug Information Portal is a free Web resource from the NLM that provides an informative, user friendly entry-way to current drug information for over 16,000 drugs. Links to sources span the breadth of NLM, the National Institutes of Health (NIH), and other government agencies. Current information regarding consumer health, clinical trials, AIDS–related drug information, MeSH pharmacological actions, PubMed biomedical literature, and physical properties and structure is easily retrieved by searching on a drug name. A varied selection of focused topics in medicine and drug–related information is also available from displayed subject headings.