A barbarism is a non-standard word, expression or pronunciation in a language, particularly one regarded as an error in morphology, while a solecism is an error in syntax. The label was originally applied to mixing Ancient Greek or Latin with other languages. It expanded to indicate any inappropriate words or expressions in classical studies, and eventually to any language considered unpolished or rude. The term is used mainly for the written language. With no accepted technical meaning in modern linguistics, the term is little used by contemporary descriptive scientists.
The word barbarism was originally used by the Greeks for foreign terms used in their language. ("Barbarism" is related to the word "barbarian"; the ideophone "bar-bar-bar" was the ancient Greek equivalent of modern English "blah-blah-blah", meant to sound like gibberish — hence the negative connotation of both barbarian and barbarism).
The earliest use of the word in English to describe inappropriate usage was in the sixteenth century to refer to mixing other languages with Latin or Greek, especially in texts treating Classics. By the seventeenth century barbarism had taken on a more general, less precise sense of unsuitable language. In The History of Philosophy, for example, Thomas Stanley declares, "Among the faults of speech is Barbarisme, a phrase not in use with the best persons, and Solecisme, a speech incoherently framed" [sic].Hybrid words, which combine affixes or other elements borrowed from multiple languages, were sometimes decried as barbarism. Thus the authors of the Encyclopædia Metropolitana criticized the French word linguistique ("linguistics") as "more than ordinary barbarism, for the Latin substantive lingua is here combined, not merely with one, but with two Greek particles". Such mixing is generally considered standard in contemporary English.