1825, East Anglian slang, perhaps from dumb ox influenced by lumbering; or from E. Anglian dialectal form of lummock "move heavily or clumsily," of uncertain origin. (from the ONLINE ETYMOLGY DICTIONARY where I am the proud sponsor of “riffraff”)
Etymology. Something I never worried about back when I first starting writing, now it’s something I obsess about . . . ever since a kindly judge in a writing contest pointed out to me that one of my favorite words, lummox, wasn’t period for my Georgian setting.
Ack! Curse you. It’s such a perfect word! I could use clod (1690) or oaf (1610), but they don’t conjure up the same image for me. There’s just something about this word (which I first encountered in Robert A. Heinlein’s The Star Beast as a child) that attracts me.
Do you have words like that? Words you are frustrated at having to leave out of a story, or that you use anyway, knowing that somewhere, someone is gritting their teeth and muttering Not Period!?