The term "under signed" is commonly used to refer to an individual or entity that has signed a document or agreement. Synonyms for "under signed" include signatory, subscriber, undersigner, and signer. These terms all indicate someone who has signed a document or contract and are often used interchangeably. Other related synonyms include delegate, proxy, and representative. It is important to note that while these terms are similar in meaning, they can have slightly different implications in certain contexts. For example, a signatory may be considered a more formal and legally binding term than a subscriber. Overall, these synonyms provide a range of options for referring to someone who has signed a document.