8.2 Dictionaries and Thesauri

• Library: A Guide to Legal Research in Virginia (Virginia CLE) (2021 Ed.)

8.2 DICTIONARIES AND THESAURI

Legal questions often turn on the meaning of words. Common words may carry new or specialized meanings when used in legal documents. A significant part of research involves the interpretation and manipulation of words and identifying the most appropriate search terms to find relevant information. Using inappropriate search terms may result in inaccurate information and lost time. Dictionaries and thesauri, both legal and non-legal, are familiar and essential references that can aid in the process of identifying search terms and locating the most appropriate resources.

Legal dictionaries operate much like their non-legal counterparts. They are alphabetical arrangements of words and phrases with identified legal meanings. One unique feature of a legal dictionary is that the definition is sometimes tied to a specific source, such as a case, that substantiates the asserted meaning of the word or phrase. Researchers must exercise care and consult the most recent or current edition of a legal dictionary because new judicial decisions, statutes, regulations, and so forth may significantly alter the existing definition or add a new meaning to a term. Additionally, the definitions provided in most dictionaries are not legally binding, so researchers should look to relevant judicial opinions and statutes in their jurisdiction for binding definitions.

A thesaurus is a dictionary of antonyms and synonyms. Researchers may use a thesaurus to locate the most accurate word among a family of related terms and to expand their existing search terms by including alternatives in the form of synonyms or antonyms.

Black's Law Dictionary,¹ commonly known as "Black's," and Ballentine's Law Dictionary,² commonly known as "Ballentine's," are the most widely used and recognized legal...