Radiantly refers to something bright and shining, mostly associated with the sun or stars. Other synonyms for radiantly include brilliantly, luminously, refulgently, and incandescently. These words suggest a dazzling and intense light that can be seen from a distance. Other synonyms that describe radiantly are glowingly, scintillatingly, resplendently, and effulgently. These words usually describe the brightness of an object in motion or a person's countenance. Additionally, words like shiningly and glitteringly are appropriate synonyms for radiantly when describing light reflecting off something or someone. In summary, radiantly has many synonyms, and the right choice of synonym depends on the context in which it is used.