The name “Lavaux” is surprising in itself as the landscape, dominated by sloping vineyards, is far from a valley that the area’s name would imply.
No valley in sight!
The rough shape of a valley etched by the Lutrive river was searched out for years in order to justify the origins of the name “La Vallée” (The Valley). Nevertheless, this potential explanation was not acceptable enough. The more current toponymical research demonstrated that the term VALLIS was primarily employed by the Carolingians (9th Century) as an administrative term in the “Midi of Gaulle” and in the French-speaking part of Switzerland. Just as PAGUS refers to a “dominion”, VALLIS refers to an “administrative territory”. This appears to be the reason behind the naming of the Lutry area. The most ancient Latin reference to vallem de Lustriaco (meaning “administrative territory of Lutry” and not “The Valley of Lutry”) dates back to 1139. A similar phrase, vallem Lustriac, is found in a document from 1316 before the French expression la Vaulx de Lustry emerged.
The main toponyms of Lavaux have two origins: the first are more ancient and directly or indirectly derive from Gallo-roman owners’ names such as Lutry, Cully, Jongny, Corsy and Corsier. The more recent names, dating back to before 1000 AD, are more wide spread such as Chenaux, Corseaux, Rivaz and Epesses. Crucially, no names from Germanic origin ending in –ens or –enges enter into the toponymical strata of Lavaux (the Marsens Tower owes its name to the monks from the Fribourg monastery that contributed to the clearing of the Dézaley area). This leads to the assumption that despite the high level of occupancy in Lavaux after the Barbarian invasion, this did not result in any changes of place names.
Source : ZUFFEREY, François, « Toponymie », in Lavaux, Vignoble en terrasses face au lac et aux Alpes, Lavaux World Heritage Site Application File for UNESCO, Cully, January 2006, pp. 114-116