The Wiktionary Glossary of Irish Slang defines skundered as Belfast term meaning really embarrassed.
I first learned this word from an Irish friend's story of a neighbor who went to a pub to talk with a girl he was seriously smitten with. He downed pint after pint to steady his nerves as he waited for her to arrive, and when she finally did, he barfed all over himself while trying to ask her out. As my friend sadly put it, the young man was skundered.
