Black's Law Dictionary is the most commonly used law dictionary in the United States. The 11th edition (2019) is available in Westlaw and in print in the Law Library's reference section on the 3rd floor at KF 156 .B53.
Other law dictionaries available in print and electronic format include:
Some foriegn language and special topic legal dictionaries are also part of the Law Library's collection.
Legal dictionaries are trustworthy sources used to look up unfamiliar terminology (including Latin words and phrases) that you encounter while conducting legal research, or in your law school courses. The most commonly used legal dictionary in the United States is Black's Law Dictionary, but there are a number of other titles available.
Like all dictionaries, legal dictionaries provide brief definitions and pronunciations of words, but legal dictionaries often offer more. Definitions, for example, may be accompanied by citations to relevant primary law sources, such as cases, which can jump start your research in an unfamiliar area of law. Some legal dictionaries contain other useful material. Black's, for example, provides references to the "West American Digest System" under which case law related to certain defined terms may be found. The print version of Black's also offers some popular "extra" appendices, including a list of legal abbreviations, a reprint of the U.S. Constitution, and a "legal maxims" section that explains the meanings of certain established principles of law as expressed in Latin phrases (e.g., Veritas est justitiae mater).
So, keep a legal dictionary handy as you begin your research. However, remember that legal dictionaries, like all secondary sources, do not contain official, authoritative pronouncements of the law. Rather, they repackage legal information in a way that is easy to understand.
Legal dictionaries work like all dictionaries. If you know the correct spelling of the word for which you are seeking a definition, the process is as straightforward as using any dictionary. Never think of a legal dictionary as a final stop in your research. While some, like Black's, are considered very trustworthy, remember that the definitions in a legal dictionary are not official, authoritative statements of the law.
To locate Black's in Westlaw, click on "Secondary Sources" in the main search screen, and then "Black's Law Dictionary" on the right side of the screen under "Tools & Resources." To access Ballentine's in Lexis, search for the title in the "Sources" section under "Browse."
While you generally will not cite to a legal dictionary, rule B15.1 (Bluepages) of The Bluebook (20th edition) is the relevant rule for non-academic legal documents. The following example is included in this rule:
Good-Faith Bargaining, Black's Law Dictionary (10th ed. 2014).
The Bluebook notes that the Bluepages retain the tradition of underlining certain text, but italics may be substituted wherever underlining is used in the Bluepages as long as the use is consistent (see p. 3). For further guidance on citing to books and other non-periodic material, see rule 15 (Whitepages).