Definition of black stump in English:

black stump

noun

Australian
informal
  • A notional marker in the outback imagined as being the last outpost of civilization:

    ‘the true stories of those who go out past the black stump only to never return’
    • ‘Qantas today assured the Gold Coast it will be flying into Tullamarine and not via the black stump at Avalon.’
    • ‘The town seems like the last frontier with its black stump, wide streets, corrugated iron houses and Burke River.’
    • ‘This is black stump territory.’
    • ‘This is backblocks Taranaki, out in the ‘never never’, ‘past the black stump’: a rough and rugged land that has beaten most settlers who dared attempt to scrape a living from the landscape.’
    • ‘We went to the small township of Milestone, about 250 miles west of Burketown in the Northern Territory — real "black stump" country.’

Origin

Early 20th century: black in the sense ‘fire-blackened’.