By contraries is an idiomatic expression that means doing something in a way that is opposite or contrary to what is expected or conventional. There are several synonyms for this phrase, including by opposites, in reverse, conversely, contrarily, and oppositely. All of these terms convey the same idea of going against the grain or doing things differently. By contraries is often used in literature and poetry, as well as in everyday conversation to describe actions or behaviors that are unexpected or unconventional. Using synonyms for this phrase can help to add variety and interest to your writing or speech, while still conveying the same meaning.