ETYMOLOGY
from rumgumption (good sense, shrewdness)
EXAMPLE
“…who’d have thought of that?–he’s a turning rumgumtious, and no mistake. Howsomdever, I must turn it over in my mind, and be even with him, somehow–I owes him one for that. I say, admiral…”
From: Varney the Vampire
By Thomas Peckett Prest, 1847
Lexicophilia 