The three inch thick 10th edition of Black's has added 7500 new entries, among them legaldygook and the "affluenza defense." Most new entries, however, are for mainstream words like reason and requisition which were never previously included. Dates in the definitions indicate the first known use of the word in English and the definitions cite statutes, cases and other sources the editor judges as helpful for a full explanation. So from "a" to "zygote" don't forget this basic tool for legal research.