-An ungrammatical combination of words in a sentence
-A minor blunder in speech
-Something deviating from the proper, normal, or accepted order
-A breach of etiquette or decorum
The city of Soloi (located in Cilicia, an ancient coastal nation in Asia Minior – contemporary Turkey) had a reputation for bad grammar. According to historians, the colonists of Soloi allowed their native Athenian Greek to be corrupted and they fell to using words incorrectly. As a result, soloikos gained a new meaning speaking incorrectly. Nowadays, solecism can refer to social blunders as well as sloppy syntax.
Example
According to the fashion critic, the actress committed a major solecism when she wore black dress on the celebratoin day.
The soldier executed a solecism of protocol when he neglected to salute his commanding officer