There are a variety of synonyms for the phrase "signs seal." Some of the most common include "approves," "certifies," "endorses," "ratifies," "stamps," and "verifies." All of these terms indicate that something has been formally approved, authenticated, or confirmed. They can be used in a range of contexts, from legal documents and contracts to official government papers. Regardless of the specific context, the use of any of these synonyms for "signs seal" suggests that the information or document in question is legitimate and credible, and has been verified by an authorized individual or institution.