Reading law was the primary method used in common law countries, particularly the United States, for people to prepare for and enter the legal profession before the advent of law schools. It consisted of an extended internship or apprenticeship under the tutelage or mentoring of an experienced lawyer. The practice largely died out in the early 20th century. A few U.S. states still permit people to become lawyers by reading law instead of attending law school, although the practice is rare.[1]
In this sense, "reading law" specifically refers to a means of entering the profession, although in England it is still customary to say that a university undergraduate is "reading" a course, which may be law or any other.