Derived from the full form of the insult: dick nankert. Used when describing a person of the most annoying personality possible by human standard. Stupidity is also an imperative feature of the subject's character, as the insultee must be slightly dumber than a rather stupid rock.
Wow! He pooped his pants on the bus? What a nankert, yo.
Yup, you're telling me, man.
Wow, brah, who would ever consider being such a tool and not join my dodgeball team?
I dunno dude, what a (dick nankert), man.