au·tum·nal \(ˈ)ȯ|təmnəl sometimes ˈȯ]d.əm- or ˈä] or ]tə-\adjective Etymology: Latin autumnalis, from autumnus + -alis -al 1.: of, belonging to, or peculiar to autumn < mild, autumnal sunshine — Nathaniel Hawthorne > 2.: produced or gathered in autumn : maturing in autumn < autumnal fruits > 3.: characterized by qualities associated with or suggested by autumn < a serene autumnal mood > • au·tum·nal·lyadverb