Wiktionary
n. (context legal pejorative English) the act of replacing an impartial interpretation of existing law with the judge's personal feelings about what the law should be
WordNet
n. an interpretation of the U.S. constitution holding that the spirit of the times and the needs of the nation can legitimately influence judicial decisions (particularly decisions of the Supreme Court) [syn: broad interpretation]
Wikipedia
Judicial activism refers to judicial rulings suspected of being based on personal or political considerations rather than on existing law. It is sometimes used as an antonym of judicial restraint. The definition of judicial activism, and which specific decisions are activist, is a controversial political issue, particularly in the United States. The question of judicial activism is closely related to constitutional interpretation, statutory construction, and separation of powers.