Started off meaning a sore one. ie in a fight you could take a sore punch. (yin = one)

But now its turned completely around and it means something is very good.

Some people still use it to describe a sore knock on the head.

Scottish slang.
oohh he took a dull yin there. (old meaning)

you seen jimmy's new car? aye its a dull yin eh? (new meaning)
by wee sax November 8, 2007
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