The story
- Proto-West Germanic · inherited from*ainnassī“oneness”
- Old English · inherited fromānnes“oneness, unity, agreement, covenant, solitude”
- Middle English · inherited fromoonnesse
- English todayoneness
From Middle English oonnesse, onnesse, from Old English ānnes (“oneness, unity, agreement, covenant, solitude”), from Proto-West Germanic *ainnassī (“oneness”), equivalent to one + -ness. Cognate with Old High German einnissī, einnissa (“unity, oneness”).
Etymology from Wiktionary, CC BY-SA 4.0.