This one popped up in a CARM thread which stated: "Luther actually coined the word 'Antinomianism' to describe Agricola's beliefs." Wikipedia states it's "a term coined by Martin Luther", so regardless if it's true or not Wikipedia will guarantee it will travel all over cyberspace as undisputed fact.
There's also a few books mentioning it. The Evangelical Dictionary of Theology states, "In fact, it was Luther who actually coined the word antinomianism in his theological struggle with his former student, Johann Agricola." The Collected Writings of James Henley Thornwell states, "The word was coined in the sixteenth century to denote the peculiar opinions of John Agricola and his followers in regard to the Law." The old Catholic Encyclopedia begins its entry on antinomianism by stating,
"The heretical doctrine that Christians are exempt from the obligations of moral law. The term first came into use at the Protestant Reformation, when it was employed by Martin Luther to designate the teachings of Johannes Agricola and his sectaries..."I have to admit I've never heard this one before. I am familiar with Luther's writings against Agricola (in fact, a volume of these writings not part of the LW set can be purchased here). Of course the concept behind the term can be traced back to troubles in the early church. I assume it's possible Luther came up with the term, but I'd be interested in seeing some better proof from better sources.