This was the first ever Australian or antipadean word and started in the ports of UK so its around 250 years old.
When passengers went aboard the ships, they where told by the captain to shout "watch under" before they puked. it would have very quicky become chunder, try shouting "watch under" just before you puke. because it started on the ships, it did not get to the british shore, until rececntly, however It has now come full circle to the uk shore with all the Aussies coming back here and of course from Aussie soaps, plus that song from the Aussie band "crowded house"
by Bushwakker February 01, 2010