Derived from the witnessing of actions of the severly mentally handicapped. Word is often accompanied with both arms in motion, hands clasped with only the index fingers extended, right arm pointed upward and left arm pointed to center of body. Meaning is: that is dumb or they, you or I am dumb.
As a Verb: He goinks at the driver for not taking his turn at the stop sign.
As a Noun: Lewis is such a freaking Goink.
As an Interjection: That was stupid, GOINK!
I should know, I made up the word goink. All other definitions are not as applicable, GOINK!