blackfin cisco

noun

: a deep-bodied whitefish (Coregonus nigripinnis synonym Leucichthys nigripinnis) with bluish-black fins that formerly inhabited the Great Lakes but is now considered highly endangered or extinct

The blackfin cisco disappeared from its once-expansive range in the Great Lakes by 1969, but at least it has managed to escape extinction: a small population, classified by the government of Canada as threatened, survives in unknown numbers in Lake Nipigon, Ontario.

—Scott Weidensaul, The Ghost with Trembling Wings, 2002

Word History

First Known Use

1909, in the meaning defined above

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