On multiple places on-line, including Wikipedia, there is information that Saint Isidore of Seville claimed that the name of the Roman god of wine, Bacchus, got his name from "baculus" meaning "walking stick", as drunk people need a walking stick to walk.
An idea of the quality of Isidore's etymological knowledge is given by Peter Jones: "Now we know most of his derivations are total nonsense (eg, he derives baculus, 'walking-stick', from Bacchus, god of drink, because you need one to walk straight after sinking a few)".
It's a lovely story to tell, but is that true? I can't find anything like that in the original works of Isidore of Seville. The only thing I could find Isidore of Seville wrote about the name "Bacchius" is the following:
Bacchius appellatus est eo, quod eo pede Bacchia, id est Liberi sacra celebrabantur.
Most of his etymologies are in the scroll 10 of Etymologiae, but it doesn't mention either "Bacchius" or "baculus" (you can search digitally here: http://www.thelatinlibrary.com/isidore/10.shtml).
So, where does that claim come from?