The act of shaking ones head in a manner which not only implies disbelief. But also a complete lack of surprise that the person causing the shake is a serial cause for your head to be shaken.
Tim: Did you hear about Kel? She carried on like a goose at the Xmas party!
Tom: shakin ghead
Tom: what did you expect
Tom: shakin ghead
Tom: what did you expect
by Hunteroftheforest November 16, 2020