Some
Australian Aboriginal languages mark the avoidance
taboo on mothers-in-law with special forms of their language. This is called
mother-in-law language or
avoidance language.
Among the Gamilaraay of Australia, until about 1895, a man could address his mother-in-law only indirectly, by going half way to her camp then facing away and shouting so that all his wife's relatives could hear. The Gamilaraay word for mother-in-law is buyal in the Namoi River dialect, or garrimaay in the Barwon River dialect.
The Dyirbal language has a special dialect called Jalnguy for use in the presence of one's mother-in-law.