The word Anzac is part of the culture of New Zealanders and Australians. People talk about the 'spirit of Anzac'; there are Anzac biscuits, and the two countries’ rugby league teams play an Anzac Day test. The word conjures up the shared heritage of two nations, but it also has a specific meaning.

ANZAC is an acronym for Australian and New Zealand Army Corps, a grouping of several divisions created early in the Great War of 1914–18. In December 1914 the Australian Imperial Force and New Zealand Expeditionary Force, both of which had just arrived in Egypt, were placed under the command of Lieutenant-General William Birdwood. Initially the term Australasian Corps was suggested for the combined force, but Australians and New Zealanders were reluctant to lose their separate identities.

No one knows who came up with the term Anzac. It is likely that Sergeant K.M. Little, a clerk in Birdwood's headquarters, thought of it for use on a rubber stamp: 'ANZAC' was convenient shorthand, and became the telegraph code word for the corps.

The Anzacs first saw action at Gallipoli on 25 April 1915. The small cove where the Australian and New Zealand troops landed was quickly dubbed Anzac Cove. Soon the word was being used to describe all the Australian and New Zealand soldiers fighting on the Gallipoli Peninsula. Later it came to mean any Australian or New Zealand soldier.

After Gallipoli

There were two Anzac corps on the Western Front from 1916, with the New Zealand Division serving initially in I Australian and New Zealand Army Corps and then, from July 1916 until January 1918, in II Australian and New Zealand Army Corps. During the Sinai–Palestine campaign the combined Australian and New Zealand Mounted Division was more commonly called the Anzac Mounted Division.

The term continued in use in later wars. An Anzac corps was briefly formed during the ill-fated 1941 campaign in Greece. During the Vietnam War, New Zealand and Australian infantry companies combined as the Anzac Battalion.