A legal dictionary provides definitions of words and phrases that have made their way into modern legal practice and may differ from what can be found in a general dictionary. Legal dictionaries may also provide references to relevant primary law and secondary sources which can help you with your research—especially when tackling an area of law that may be new and unfamiliar.
Black's Law Dictionary is considered by many to be the preeminent legal dictionary for American Law. It can be found among the Library’s print collection (Reserve KF156 .B53) and is also available electronically on Westlaw. With over 55,000 law-related words and phrases, it is touted as “the most practical, comprehensive, scholarly, and authoritative law dictionary ever published.”
A number of other legal dictionaries can also be found online, and without having to subscribe to such services as Westlaw. Below is a curated list of legal dictionaries that are accessible online at no cost. Bear in mind, however, that not all Internet sources are updated regularly, URLs change, and links rot. It is best to check for accuracy and current information.
Legal Information Institute, Cornell University Law School
Wex is a free legal dictionary and encyclopedia sponsored and hosted by the Legal Information Institute at the Cornell Law School. The entries are collaboratively created and edited by legal experts, mostly legal academics and distinguished practitioners, who have demonstrated expertise in a particular area of law.
Findlaw Legal Dictionary
The FindLaw Legal Dictionary provides free access to over 8,200 definitions of legal terms. Search for a definition or browse its legal glossaries. Many of the entries are sourced from Merriam-Webster's Dictionary of Law (1996).
ALM Media Properties, LLC
Law.com's Dictionary can be searched in 3 different ways: Search by word or phrase, find all definitions that include a specific term, or browse by the first letter of a word or phrase. The entries originate from The People's Law Dictionary by trusted authorities, Gerald and Kathleen Hill.
Nolo's Free Dictionary of Law Terms and Legal Definitions
Nolo’s Free Dictionary of Law is a browsable source for plain-English definitions for legal terms. Nolo has been a recognized publisher of self-help legal materials since 1971 and make much of their content available for free online. A free iOS app version is also available in the App Store. An internet connection is not required to use the app.
Duhaime's Law Dictionary
Duhaime's Law Dictionary offers definitions of legal terms written in plain language by Canadian lawyer Lloyd Duhaime, along with extensive cross references as well.
TheFreeDictionary.com by Farlex
The main source of TheFreeDictionary's legal dictionary is West's Encyclopedia of American Law, 2d ed., which contains more than 4,000 entries detailing terms, concepts, events, movements, cases, and individuals significant to United States law. The legal dictionary also incorporates over 3,000 terms from The People's Law Dictionary by Gerald and Kathleen Hill. An app version is also available with free offline access from the App Store and from Google Play.
John Bouvier's Law Dictionary
One of the first American law dictionaries compiled, this set of three books was originally published by John Bouvier in 1839 which distinguished the terminology of the American legal system from its English counterpart. It is useful for understanding obsolete terms found in older authorities. This digitized version draws from the 1856 revised 6th edition.
Merriam-Webster's Law Dictionary
Search more than 10,000 legal words and phrases for clear definitions written in plain language from the dictionary experts at Merriam-Webster.
Provides definitions with browsable list of legal topics.
Georgetown Law Library maintains an online repository that includes digitized copies of historical dictionaries dating from 1575 to 1916, including Black’s Law Dictionary.
Legal Term and Law Dictionary
This Dictionary is based on the 1856 Edition of the Bouvier’s Law Dictionary. Although the legal dictionary is pretty old, many of the definitions are still proper (since most legal terms in use today were coined well before 1856). This database contains over 6,500 definitions. Simply type in the correct spelling of the search term and hit the search button. If you are not sure about the correct spelling of the term, then enter the first few letters of the term. You can also browse definitions alphabetically.
Glossary of Legal Terms
United States Courts
A browsable glossary of commonly used legal terms from the U.S. Courts.
Glossary for the New York State Legislative Process
New York City Bar Association
The NYCBA has created an excellent glossary of terms and phrases frequently used during the New York State legislative process.
The Legal Aid Society