Rubber-stamped refers to something that has been approved or authorized without much thought or scrutiny. Some synonyms for rubber-stamped could be approved, authorized, validated, or confirmed. However, antonyms for rubber-stamped would be adjectives like scrutinized, examined, reviewed, evaluated, or analyzed. These words imply a careful and thorough evaluation of something before it is approved or authorized. A rubber-stamped document or decision may lack originality or thoughtfulness, whereas one that has been carefully scrutinized is likely to be more innovative and impactful. Hence, it's always advisable to avoid rubber-stamping things and instead focus on analyzing or reviewing them for better outcomes.