The story
- Old English · inherited fromwella
- English todayWells
From Old English wella, genitive plural of well (“spring”), in reference to a residence near a group of springs. The original use of the genitive case here would've indicated origin. The -s ending of the modern form would be added later on upon reanalysis after the breakdown of the case system (outside of pronouns) that occurred in the development of English.
Words from the same roots
Old Englishwella all →
Etymology from Wiktionary, CC BY-SA 4.0.