An interesting example is "weans" vs "bairns" for children... first time I heard the former I had no idea what people were talking about. "Weans" seems to be a

An interesting example is "weans" vs "bairns" for children... first time I heard the former I had no idea what people were talking about. "Weans" seems to be a shortened form of "wee ains" and "bairns" is from Old English: https://en.wikipedia.org/wiki/Bairn https://en.wikipedia.org/wiki/Bairn