For some time now, some of my on-line friends have advised me to provide a version of CassidySlangScam without the invective aimed at Cassidy and his supporters. In response to that advice, I am working on providing a glossary of the terms in Cassidy’s ludicrous book How The Irish Invented Slang with a short, simple and business-like explanation of why Cassidy’s version is wrong.
According to Daniel Cassidy’s etymological hoax, How The Irish Invented Slang, spunk comes from the Gaelic or Irish word sponnc and spunky from sponncach. Cassidy is completely right about this. It probably does come from Gaelic or Irish. Sponnc (or sponc in modern spelling) does mean tinder or material to light a fire and the metaphorical use of this to mean fiery personality, courage or semen is quite clear. However, though Cassidy says that the OED claims that spunk is of uncertain origin and possibly related to punk and funk, what he doesn’t tell us is that the other English dictionaries already give the Gaelic or Irish derivation of spunk and they did so a long time before Cassidy started on his etymological project.