Ever so often is a phrase used to describe something that occurs periodically or at irregular intervals. Synonyms to describe the same include sporadically, occasionally, infrequently, irregularly, intermittently, from time to time and rarely. Each of these words indicates an event or occurrence that doesn't take place frequently, with varying degrees of irregularity ranging from sporadic to rare occurrences. These synonyms can be used interchangeably in place of ever so often depending on the context of the text. Using synonyms in your writing helps you vary sentence structure, tone, and enhance readability.