Definition of Jacko in English:

Jacko

Pronunciation /ˈdʒakəʊ/

noun

  • 1Australian The laughing kookaburra, Dacelo novaeguineae.

  • 2Australian, New Zealand Military
    slang, derogatory The Turkish army collectively, during the First World War (1914–18).

Origin

Early 20th century; earliest use found in The Bulletin. From Jack + -o.