The body of law which originated in England, and is primarily judge-made law.

 Encyclopedia Britannica, 2nd Edition.

COMMON LAW, like “civil law,” a phrase with many shades of meaning, and probably best defined with reference to the various things to which it is opposed. It is contrasted with statute law, as law not promulgated by the sovereign body; with equity, as the law prevailing between man and man, unless when the court of chancery assumed jurisdiction; and with local or customary law, as the general law for the whole realm, tolerating variations in certain districts and under certain conditions. It is also sometimes contrasted with civil, or canon, or international law, which are foreign systems recognized in certain special courts only and within limits defined by the common law. As against all these contrasted kinds of law, it may be described broadly as the universal law of the realm, which applies wherever they have not been introduced, and which is supposed to have a principle for every possible case. Occasionally, it would appear to be used in a sense which would exclude the law developed by at all events the more modern decisions of the courts.

Blackstone divides the civil law of England into lex scripta or statute law, and lex non scripta or common law. The latter, he says, consists of (1) general customs, which are the common law strictly so called, (2) particular customs prevailing in certain districts, and (3) laws used in particular courts. The first is the law by which “proceedings and determinations in the king’s ordinary courts of justice are guided and directed.” That the eldest son alone is heir to his ancestor, that a deed is of no validity unless sealed and delivered, that wills shall be construed more favourably and deeds more strictly, are examples of common law doctrines, “not set down in any written statute or ordinance, but depending on immemorial usage for their support.” The validity of these usages is to be determined by the judges – “the depositaries of the law, the living oracles who must decide in all cases of doubt, and who are bound by an oath to decide according to the law of the land.” Their judgments are preserved as records, and “it is an established rule to abide by former precedents where the same points come again in litigation.” The extraordinary deference paid to precedents is the source of the most striking peculiarities of the English common law. There can be little doubt that it was the rigid adherence of the common law courts to established precedent which caused the rise of an independent tribunal administering justice on more equitable principles – the tribunal of the chancellor, the court of chancery. And the old common law courts – the king’s bench, common pleas and exchequer – were always, as compared with the court of chancery, distinguished for a certain narrowness and technicality of reasoning. At the same time the common law was never a fixed or rigid system. In the application of old precedents to the changing circumstances of society, and in the development of new principles to meet new cases, the common law courts displayed an immense amount of subtlety and ingenuity, and a great deal of sound sense. The continuity of the system was not less remarkable than its elasticity. Two great defects of form long disfigured the English law. One was the separation of common law and equity. The Judicature Act of 1873 remedied this by merging the jurisdiction of all the courts in one supreme court, and causing equitable principles to prevail over those of the common law where they differ. The other is the overwhelming mass of precedents in which the law is embedded. This can only be removed by some well-conceived scheme of the nature of a code or digest; to some extent this difficulty has been overcome by such acts as the Bills of Exchange Act 1882, the Partnership Act 1890 and the Sale of Goods Act 1893.

The English common law may be described as a pre-eminently national system. Based on Saxon customs, moulded by Norman lawyers, and jealous of foreign systems, it is, as Bacon says, as mixed as the English language and as truly national. And like the language, it has been taken into other English-speaking countries, and is the foundation of the law in the United States.

 Black’s Law Dictionary, 2nd Edition.

As distinguished from the Roman law, the modern civil law, the canon law, and other systems, the common law is that body of law and juristic theory which was originated, developed, and formulated and is administered in England, and has obtained among most of the states and peoples of Anglo-Saxon stock. Lux v. Haggin, 69 Cal. 255, 10 Pac. 674. 2. As distinguished from law created by the enactment of legislatures, the common COMMON LAW 227 COMMON PLEAS law comprises the body of those principles and rules of action, relating to the government and security of persons and property, which derive their authority solely from usages and customs of immemorial antiquity, or from the judgments and decrees of the courts recognizing, affirming, and enforcing such usages and customs; and, in this sense, particularly the ancient unwritten law of England. Western Union Tel. Co. v. Call Pub. Co., 181 U. S. 92, 21 Sup. Ct. 5G1, 45 L. Ed. 7G5; State v. Buchanan, 5 Har. & J. (Md.) 3G5, 9 Am. Dec. 534; Lux v. Ilaggin, G9 Cal. 255, 10 Pac. G74; Barry v. Port Jervis, 64 App. Div. 268, 72 N. Y. Supp. 104. 3. As distinguished from equity law, it is a body of rules and principles, written or unwritten, which are of fixed and immutable authority, and which must be applied to controversies rigorously and in their entirety, and cannot be modified to suit the peculiarities of a specific case, or colored by any judicial discretion, and which rests confessedly upon custom or statute, as distinguished from any claim to ethical superiority. Klever v. Seawall, 65 Fed. 395, 12 C. C. A. 661. 4. As distinguished from ecclesiastical law, it is the system ofjurisprudence administered by the purely secular tribunals. 5. As concerns its force and authority in the United States, the phrase designates that portion of the common law of England (including such acts of parliament as were applicable) which had been adopted and was in force here at the time of the Revolution. This, so far as it has not since been expressly abrogated, is recognized as an organic part of the jurisprudence of most of the United States. Browning v. Browning, 3 N. M. 371, 9 Pac. 677; Guardians of Poor v. Greene, 5 Bin. (Pa.) 557; U. S. v. New Bedford Bridge, 27 Fed. Cas. 107. 6. In a wider sense than any of the foregoing, the “common law” may designate all that part of the positive law, juristic theory, and ancient custom of any state or nation which is of general and universal application, thus marking off special or local rules or customs. As a compound adjective “common-law” is understood as contrasted with or opposed to “statutory,” and sometimes also to “equitable” or to “criminal.”

 WordNet 3.6

  • (n) a law established by following earlier judicial decisions
  • (n) a system of jurisprudence based on judicial precedents rather than statutory laws “common law originated in the unwritten laws of England and was later applied in the United States

Webster’s Revised Unabridged Dictionary

  • a system of jurisprudence developing under the guidance of the courts so as to apply a consistent and reasonable rule to each litigated case. It may be superseded by statute, but unless superseded it controls.

Cases and Materials on the Law of Torts at 4 n.9 (George C. Christie & James E. Meeks, eds., 2d ed., 1990)

Common law is a term of diverse meanings.  Depending on the context, it can mean any or all of the following: (1) the law common to all England and not confined to a particular locality — the law enforced in royal courts; (2) a system of law that is developed case-by-case by the courts as opposed to law established by statute; (3) the law of the English speaking world whose origins are in English law as opposed to the law of the continent (or in Scotland) which developed out of Roman law or as opposed to any other system of law whose roots are not in English law.  As to meaning (2), the situation is complicated by the fact that much of what we consider of judicial origin probably originated in statutes or royal decrees the are now lost.