In 2005, I asked Merriam-Webster the following question. Senior Editor, Linda Picard Wood, replied as follows.
Q: People usually refer to the judges of the U.S. Supreme Court as “justices,” whereas all inferior judges are usually called “judges.”
- Is this accurate?
- Is there any difference between a “justice” and “judge”?
A: Members of the Supreme Court of the United States are usually referred to as “justice,” but so are judges of other high courts.
The level at which they administer justice (e.g., a district vs. appellate court) is the only difference between a “judge” and a “justice.” Otherwise, the words mean the same thing. (The day to day duties of a judge and a justice undoubtedly differ, too.)
Interestingly, the word “justice” in this sense appears to be the older of the two terms. The Oxford English Dictionary traces the earliest date of “justice” to mean an administrator of the law back to before the year 1200. The earliest known use of the word “judge” with this meaning goes back to around the year 1300.