Importantly is a word that is widely used in the English language to denote the significance or importance of something. There are many synonyms that can be used in place of the word importantly, which have specific meanings in different contexts. Some of the common synonyms of importantly are significantly, crucially, notably, primarily, essentially, fundamentally, decisively, and vitally. Depending on the tone of the sentence and the context in which it is used, any of these synonyms can be used to convey the meaning of importance. Moreover, using synonyms can also add variety and interest to one's writing by avoiding repetition and monotony.