The phrase "more twelfth" is an uncommon construction in the English language, so there are few direct synonyms for it. However, there are a number of alternate phrases and expressions that can be used to convey a similar meaning, such as "more than the usual dozen" or "beyond the standard twelve." Another option might be to use a more quantitative term, such as "thirteen" or "a baker's dozen," which would imply that there is one additional item beyond the traditional twelve. Other possibilities might include variations based on the context in which the phrase is being used, such as "bonus item" or "extra unit".