What is an oxidised wine?
Wiki has a fair bit to say on the subject, IIRC. Or maybe I was just googling.
But, in brief, tastes a bit cardboardy and flat, and quite likely sherry-ish.
Now, I have a parsnip which is a bit sherryish, but not really carboardy, and it's not getting worse with age so I think it may just be a weird effect of the brown sugar I used in it rather than serious oxidation. I'll stick to ordinary sugar next time: parsnips should give a dry white, not a tawny!