Keenan Kmiec has a fascinating article tracing the meaning of "judicial activism" entitled, appropriately, "The Origin and Current Meanings of 'Judicial Activism.'" It's well-written, short, and as the table of contents demonstrates, comprehensive:
I. Early History of the Term "Judicial Activism"
A. In Search of the Earliest Use
B. First Recorded Use: Arthur Schlesinger in Fortune Magazine
C. Early Usage of "Judicial Activism"
D. Early Scholarly Examination of Judicial Activism
E. First Judicial Use of "Judicial Activism": Judge Joseph C. Hutcheson, Jr
F. Other Noteworthy Discussions of "Judicial Activism" in Judicial Opinions
II. Definitions of Judicial Activism
A. Striking Down Arguably Constitutional Actions of Other Branches 1463
B. Ignoring Precedent
1. Vertical versus Horizontal Precedent
2. Constitutional versus Statutory versus Common Law Precedents
C. Judicial Legislation
D. Departures from Accepted Interpretive Methodology
E. Result-Oriented Judging