"Serious monies" is a phrase used to refer to large sums of money that have significant financial value. However, there are several synonyms that one can use instead of the phrase. For instance, the term "substantial funds" can be used to refer to the same meaning as the phrase. Likewise, the phrase "considerable capital" can be used to describe significant financial resources. Other synonyms include "significant wealth," "ample finance," and "vast resources." The use of these synonyms may vary depending on the context in which they are used, but they all connote the same meaning of substantial financial value.