The story
- Middle English · inherited frompadlock
- English todaypadlock
From earlier pad lock (19th c.); Middle English padlock, padlokke, from pad-, of unknown origin, + lok (“lock”). Perhaps originally a lock for a pad (“gate”), or a gate opening to a path, or a lock for a basket or pannier, from UK dialect pad (“a pannier”).
Etymology from Wiktionary, CC BY-SA 4.0.