To Jeff, The meaning of "Fair Dinkum" goes back to the time of the gold rush era in Aussie. A man would walk into a pub after a strike and call out "Fair Drinking". Meaning he would shout the bar for a set amount of drinks. Being the pisspots they were at the time it was shortned and took on new meanings ie: are you serious? I hope this has answered your query. Merry Christmas to all and may your beers always be cold!!!