Is it ensure, insure, or assure?
early 15c., "case which may be taken as a rule in similar cases," from Middle French precedent, noun use of an adjective, from Latin praecedentum (nominative praecedens), present participle of praecedere "go before" (see precede). Meaning "thing or person that goes before another" is attested from mid-15c. As an adjective in English from c.1400. As a verb meaning "to furnish with a precedent" from 1610s, now only in past participle precedented.
A previous ruling by a court that influences subsequent decisions in cases with similar issues.
in law, a judgment or decision of a court that is cited in a subsequent dispute as an example or analogy to justify deciding a similar case or point of law in the same manner. Common law and equity, as found in English and American legal systems, rely strongly on the body of established precedents, although in the original development of equity the court theoretically had freedom from precedent. At the end of the 19th century, the principle of stare decisis (Latin: "let the decision stand") became rigidly accepted in England. In the United States the principle of precedent is strong, though higher courts-particularly the Supreme Court of the United States-may review and overturn earlier precedents.