SOLECISM

A grammatical mistake, a blunder, or any deviation from correct idiom is, in English, termed a solecism. The word’s history can be traced to the Greek city of Soloi in ancient Cilicia, which was in what is today southern Turkey.
Soloi was far removed from the Greek homeland. Because of the distance, the colonists developed a dialect of their own. When the snooty sophisticates back home paid a visit to Soloi, they were shocked to hear their mother tongue «debased» by corrupt dialect of Greek. The Greeks termed what they heard soloikos, meaning speaking incorrectly. The noun that evolved was soloikismos. Latin borrowed it as soloecismus, from
which came the English word used today — solecism. That English word has immortalized the substandard form of Attic dialect.