Indian summer

The story

Of North American origin, exact etymology uncertain. The most plausible suggestions are that Native Americans (or American Indians) called it a form of “summer” due to harvesting late plants or preparing for winter, or that European settlers coined it due to various Native American activities in this season, or due to the weather phenomenon being associated with regions inhabited by Native Americans. Alternatively, the use of the word Indian may indicate something deviating from a Eurocentric norm as counterpart: compare terms like Indian bread, Indian corn.

First known use, by meaning

• from late 18th c., popularized in the early 19th c. A stretch of sunny and warm, often hazy, days during late autumn.
• from early 19th c. The late autumn of life; a late flowering of activity before old age.