I'm surprised I overlooked this time-honored gnomeword. No doubt this is one that gnomes crafted when the were bored. Instead of saying "This is boring" the damned gnomes had to say something like "This is so humdrum!" Which probably prompted whatever non-gnome around them to say "What the fuck are you even saying? Why don't you get off that fucking mushroom and talk clearly?"
hum·drum
adj.
Lacking variety or excitement; dull. See Synonyms at boring, dull.
n.
Monotonous talk or routine.
[Probably from hum.]