au‧tumn, n. /ˈɔː.təm/
Latin portmanteau word of aurum (“gold”) and vertēre (“to change”). (For the relevant conjugation, see Vertumnus.) Autumn is the time of year at which the leaves become golden shades of yellow and orange.
The late-autumn name of “cuprumn” fell into disuse due to its being nearly impossible to distinguish from copper’s cuprum.