eau, which would most likely be french origin would be
pronounced 'oh' eg plateau (plat-oh)
I don't see why bott would become bort although the french are
weird so maybe, but the ending is certainly (if of french origin at
least) oh, so I'd pronounce it bot-tr-oh or bort-tr-oh if there's
anything to the bor suggestion
ok how to pronounce bordeux?
it's actually bordeaux, 'eaux' or simply 'aux'
is pronounced the same as 'eau' (oh) - eg chateaux (shat-oh),
Auxerre (oh-z-air) - so it is said 'board-oh'