An Anzac is a soldier from Australia or New Zealand, especially one who fought in the First World War. The name comes from the first letters of Australian and New Zealand Army Corps, the group those soldiers belonged to. People write Anzac or ANZAC, and say it AN-zak. Though actually, in Australia and New Zealand this is not a light word, and it is not a nickname for anyone from those countries today. It carries memory and respect: very young men sent far from home, many of them to a long, hard fight in 1915 at a place called Gallipoli. Anzac Day, on 25 April, is when those countries stop to remember the dead and the ones who came back changed. You would not use it as a joke, a brand, or a casual label for a tourist.