numbskullery 

Stupid acts. Used by Mr. Burns in The Simpsons

Mr. Burns: "I can't take much more of your blundering numbskullery"

numbskullery by Joe R. April 4, 2006

Numskullduggery 

An amalgamation of "Numbskull" and "Skullduggery". Can be employed to describe an amusing, risqué, or banter-incucing act, as perpetrated by a numbskull.
Although not in common usage, would work best used by an Englishman, ideally a gentleman from the East End of London.

"Wot on the Sweet Lord's green erf joo fink you woz ap to larst night 'Arry?"

"Wojoomean boss? We wos jus 'avin a larf. Not mar fault the boys in blue turned ap!"

"Well yore faakin' numskullduggery nearly got us locked ap you tit!"

Numskullduggery by Kilpin May 29, 2007

numbskulled 

the state of inebriation whereupon a shy or old metal head will mosh it up and likely be in danger of sustaining severe injury.

Jeremy was so numbskulled last night, he totally jumped in the pit with the karate kids and slipped a fuckin' disc!

numbskulled by Ross Sewage April 17, 2006