Overshadower is a word that implies overshadowing or rendering someone or something less significant or important. However, there is an entire list of synonyms for this word that can be used to describe this phenomenon. Some of the possible words that come to mind include outshine, eclipse, dominate, overshadow, outweigh, and overrule. Other potential synonyms for overshadower could be outdo, surpass, and exceed. All of these words have the same fundamental meaning, but they are expressed in different ways. Depending on context and intention, any of these synonyms could work equally well. Ultimately, finding the right word for the situation requires careful consideration of the context in which it is being used.