Noun. The name of a delinquent, usually of European descent, in which whatever comes out of the person's mouth is illegible, illogical, or plain misunderstood. Instead of dingbat, an 'a' was added on to make the person seem more preposterous than being an actual ding bat.
Verb. 1)To act in a vagrant, childish manner, as if one had brain damage at an early age that manifested into something more serious.
"Look at him, acting like he's the king of everything! What a dingbata!"
"You're such a dingbata. Everything you say makes no sense!"