Autumnal is an adjective that means ‘characteristic of autumn.
The word autumn comes from Latin and has always meant ‘the fall,’ as in the season that follows summer. Our word of the day ads and N-A-L to give us an adjective to describe anything related to this season. Here’s an example:
Football has always been my favorite autumnal activity. As soon as those leaves hit the ground, I’m ready to hear somebody’s ankle snap on the field.