n. [ L. auctumnus, autumnus, perh. fr. a root av to satisfy one's self: cf. F. automne. See Avarice. ] 1. 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. [ 1913 Webster ]

☞ In England, according to Johnson, autumn popularly comprises August, September, and October. In the southern hemisphere, the autumn corresponds to our spring. [ 1913 Webster ]

2. The harvest or fruits of autumn. Milton. [ 1913 Webster ]

3. The time of maturity or decline; latter portion; third stage. [ 1913 Webster ]

Dr. Preston was now entering into the autumn of the duke's favor. Fuller. [ 1913 Webster ]

Life's autumn past, I stand on winter's verge. Wordsworth. [ 1913 Webster ]

a. [ L. auctumnalis, autumnalis: cf. F. automnal. ] 1. Of, belonging to, or peculiar to, autumn; as, an autumnal tint; produced or gathered in autumn; as, autumnal fruits; flowering in autumn; as, an autumnal plant. [ 1913 Webster ]

Thick as autumnal leaves that strow the brooks
In Vallombrosa. Milton. [ 1913 Webster ]

2. Past the middle of life; in the third stage. [ 1913 Webster ]

An autumnal matron. Hawthorne. [ 1913 Webster ]

Autumnal equinox, the time when the sun crosses the equator, as it proceeds southward, or when it passes the autumnal point. --
Autumnal point, the point of the equator intersected by the ecliptic, as the sun proceeds southward; the first point of Libra. --
Autumnal signs, the signs Libra, Scorpio, and Sagittarius, through which the sun passes between the autumnal equinox and winter solstice. [ 1913 Webster ]