when something someone does is obtrusivly stupid. It is often preceded by the word "utter". This word comes from the word moron. It is basicly the same as stupidity only funnier to say.
person 1: "Im going to tease that wild rabid bear with huge claws and see if it catches me"
person 2: "WHAT!? that just utter moronicy!"
The labour party's policies are just utter moronicy