The term directly correlates to the head of Nazi propaganda, Joseph Goebbels. Grobble-bobble can describe a person who is spreading false information. Grobble-Bobblery can also be used to describe the act of being a Grobble-Bobble.
She is a grobble-bobble when she told her kids that vaccines are bad.
Shelby: "Kris what are ya gonna do about that empty space in yer paintin'?"
Kris: "Eh, Ms. Frels wants us to fill all the space so i'll probably just fill it with a bunch of gobbly goop and call it good"
1. in tabletop gaming, a small annoying monster that does little more than irritate
2. in LRP a particularly vicious and nasty hostile creature
3. in LRP a powerful or useful item used against players
4. an unpleasant experience (usually referred to as being gribbled)