"Am tantamount" is a phrase that is often used to describe something that is equivalent or similar in value or importance. Some synonyms for "am tantamount" might include "am equivalent," "am comparable," "am parallel," or "am similar." These phrases all convey the same basic idea that something is equal in significance or worth. Similarly, other synonyms for "tantamount" might include "commensurate," "correlative," or "equivalent." Whether you are trying to describe the importance of a particular event or action, or simply looking for ways to express equivalence, these synonyms can help to add variety and precision to your language.