The story
- Old English · inherited fromadūn
- Middle English · inherited fromadoun
- English todayadown
From Middle English adoun, from Old English adūn, earlier ofdūne (“down”), from of dūne (“off the hill”) (compare Latin ad vallum > Old French à val, used in the same way).
Words from the same roots
Old Englishadūn all →
downright
Etymology from Wiktionary, CC BY-SA 4.0.