The term "by-word" is commonly used to refer to a phrase or expression that is widely known and frequently used. However, there are several synonyms that can be used in place of "by-word" to add variety and nuance to your writing or speech. Examples include "proverb," "maxim," "saying," "adage," "catchphrase," and "cliche." Each of these words has a slightly different connotation and usage, but all can be used to denote a commonly used phrase or expression. Experimenting with different synonyms can help to keep your writing fresh and engaging, and prevent repetition or monotony.