black swan

noun

1. an Australian swan, Cygnus atratus, having mostly black plumage and a red bill.

2. an occurrence or phenomenon that comes as a surprise because it was not predicted or was hard to predict (often used attributively).

   a disastrous black-swan event that only appeared obvious in hindsight.

black swan

noun

1. a large Australian swan, Cygnus atratus , that has a black plumage and red bill

2. a phenomenon that occurs even though it had been thought to be impossible

Word History and Origins

Origin of black swan¹

black swan ( def. 2 ) from the belief that all swans were white, before the first sighting of Australian black swans

Word History and Origins

Origin of black swan¹

sense 2 from the fact all swans were thought to be white until black swans were discovered in Australia

Example Sentences

That implies that barring a black swan event, the current easing cycle is close to done.

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But whether Eve’s inner black swan will win out over her white one is never in question.

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A “black swan” moment — a tipping point for justice — is approaching.

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The heat wave "was so extreme, it's tempting to apply the label of a 'black swan' event, one that can't be predicted," said Bartusek.

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But experts have told the BBC that this was likely a "black swan" occurrence of freak weather - and that no-one is necessarily at fault.

Read more on BBC