The third season of the year, or the season between summer and winter, often called "the fall." Astronomically, it begins in the northern temperate zone at the autumnal equinox, about September 23, and ends at the winter solstice, about December 23; but in popular language, autumn, in America, comprises September, October, and November.
- The season of the year between summer and winter, lasting from the autumnal equinox to the winter solstice and from September to December in the Northern Hemisphere; fall.
- A period of maturity verging on decline.
- Of, having to do with, occurring in, or appropriate to the season of autumn: autumn foliage; autumn harvests.
- Grown during the season of autumn: autumn crops.