what does that mean
'Yes, of course, that is true…I hadn't considered that point…But what I meant was, it sounds more like a rather idiotic kind of hoax. Perhaps some convivial idiot who had had one over the eight.’
‘Comment? Nine? Nine what?’
'Nothing—just an expression. I meant a fellow who was tight. No, damn it, a fellow who had had a spot too much to drink.’
that is some dialogue in Poirot and Hastings from Agatha Christie's novel.
I don't understand about "one over the eight" "Comment? Nine? ", what does that mean?