Green’s Dictionary of Slang

hurry up! quickly! thus ext. get an iggri on! hurry up!

1924		(con. WWI) A.G. Pretty Gloss. of Sl. [...] in the A.I.F. 1921–1924 (rev. t/s) n.p.: igaree. Quick (Arabic) A peculiar feature of A.I.F. slang was the combination of words adapted from different languages i.e. ‘Igaree at the toot,’ run away quickly from the latter portion of the phrase being derived from the French ‘toute.’.
1930		(con. WWI) Brophy & Partridge Songs and Sl. of the Brit. Soldier 131: Iggry. — Hurry up! (from the Arabic iggri). The Australians appropriately named a crossing in Bullecourt: Iggry Corner.
1945		John O’London’s Wkly Issues 1250–75 210: We have become so accustomed to shouting ‘iggery’ to slow-moving natives.
1946		D. Hill ‘Chalky’ in Lehmann Penguin New Writing No. 28 173: Come on, Chalky [...] get an iggri on!