In a mid-late-20th-century British play the name and author of which I have forgotten, I once read the following line, spoken as a fond reminiscence by a sodden erstwhile Etonian or Harrovian or whatever: “Sodomy, buggery, boarding-school-duggery…”
And so the word skulduggery has ever since had for me an overtone of anal sex. The duggery certainly fits (as it were), digging in the backyard and all that. The skul (sometimes spelled skull in this word) is more reminiscent of fellatio, of course: skull-duggery would be skull-fuckery, no?
Well, there is good news yet for any skulking skull kings out there. Skulduggery may refer to shady deeds and dark doings, underhanded things, intrigues and trickery, but its source is a word for, well, doing things in dark places and shady areas, under the hand or other bodily parts, and turning intriguing tricks.
That source word is sculduddery. It was a Scots word, a term that a fuddy-duddy might use to refer to diddling. Its scope seems to have been broad: a scullery lass with a doddering fool, or a rascal with a diadem and, erm, his saddle steed. It could be any “breach of chastity” (as the OED has it). Here’s a nice quotation from The Wonder, a 1715 play by Susanna Centlivre: “But I’m seer there’s na sike honest People here, or there wou’d na be so muckle Sculdudrie.” A note explains that this means fornication. (Editor leans over, stage-whispers in your ear: “He means for-ni-ca-tion.”) Other quotes expand it to adultery. Basically, it means fucking outside of wedlock.
OK, but what about boarding-school-duggery? We may count that as fucking now, but ramming it up the poop-chute (as Frank Zappa put it) was not always seen in the same light (or darkness). Well, no fear: the widest (as it were) definition of sculduddery included any obscenity, even the utterance thereof. Anal sex must certainly count. As, of course, does skull-diggery. Or talking about it. Basically, sculduddery is this article and everything it describes.
But skulduggery? When the term shifted its consonants deeper in the throat, from d to g, and brought out more plainly the skull overtone, it kept the sense of mischief and dark deeds but ran with the skulls and daggers and gravediggers and so forth.
Which is not to say that you can’t use it to refer to fucking, especially underhanded, i.e., clandestine and sneaky. Whether you can use it to refer the other underhanded or overhanded kind of thing… well, can you have skulduggery for one? I’ll leave it to you to dig for that in your own skull. (As it were.)