According to the Random House Dictionary of the English Language (New York: Random House, 1966, 490), etymology treats "the study of historical linguistic change," and "the derivation of a word"-including "an account of the history of a particular word."
I studied etymology as part of my graduate work in language and linguistics, and it became useful to my doctoral work-my dissertation being Literary Investigation (1987).
My history of the word detective appeared as "Detective: Uncovering the Mysteries of a Word" in Skeptical Inquirer 37:6, November/December 2013, pp. 14-17).
Other word derivations that I researched and applied to my cases over the years were stampeding (which helped expose as fakes the Beale treasure papers-see my Mysterious Realms, 1992, 53-67), snake oil (see my Real-Life X-Files, 2001, 164-169, and a follow-up, "Snake Oil: A Guide for Connoisseurs," Skeptical Briefs 16:3, September 2006, 7-8), veronica (a corruption of vera iconica-see my The Science of Miracles, 2013, 111-112, 234-236), and baloney (which I suggest is a corruption of the Irish blarney-see my Adventures in Paranormal Investigation, 2007, 242-246).