A mild slang name for a penis, supposedly less offensive that cock, prick, or dick, it does not have the fecal connotations of dingleberry but is used to describe the penis in much the same circumstances by much the same people. In addition it can also be used as a mildly disparaging term for a person who has exasperated you by doing something atypically stupid.
"I had to rush like hell to get here on time. I was halfway here when I remembered I'd left the contract in my desk at home and had to go back for them, I felt like a right dooberry."
1.In one of the episodes in Phineas And Ferb, doofenshmirtz uproots a whole clock tower for convenient access and information of time; instead of buying a simple clock or a watch, known as Doofenshmirtzing.
2.Why are you doofenshmirtzing your work?
The best villain ever to exist, he can create things that are stronger than the infinity gantlet, but his plans get foiled by some blue duck beaver thing.