[thefabfive]

From what I see it does indeed mean 'bottom'. The second result on Google is a Wikipedia article on what I believe is the 'bottom quark' (as in subatomic physics).

Other interpretations of 'bottom' seem to be 'sole of the shoe' or 'floor'. Maybe the high overture count comes from 'floor'. It is also used to describe the lowest point on a graph, like 'stock market bottom' or 'valley'. Anyway, looks like it's got many generic meanings which is always good.

I am not a native speaker so I can't verify this, but that's what is looks like to me.