Today I encountered the word "batso" and I understood from context it meant "crazy". It interested me because it sounds like an Italian word "pazzo" which means "crazy".
I looked it up and it indeed means "crazy", but has nothing to do with "pazzo". It's just bats + o, there's also nuts + o. I guess these are very American constructions. Am I right? Do British people use these words and such words?
Could you give more example of such words with "o" at the end? Does this o-adding sound right with all adjectives?