- 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 harvest or fruits of autumn. - The time of maturity or decline; latter portion; third
stage.
Meaning of 'autumn' (Princeton's WordNet)
1 . autumn
[ n]
Meaning (1): - the season when the leaves fall from the trees