The term "third party" is commonly used in legal and business contexts to refer to someone or something outside of a direct transaction or relationship. There are several alternative phrases that can be used as synonyms for this term, depending on the context. Some potential options include "external party," "outsider," "non-affiliated party," and "independent entity." In the context of insurance, "claimant" or "third-party claimant" may be used to refer to individuals or organizations filing claims for damages or losses against policyholders. In any case, it is important to carefully consider the specific meaning and implications of each potential synonym before choosing the most appropriate term for a given situation.