The phrase "through what medium" refers to the means or method by which something is conveyed or communicated. There are several synonymous expressions to use instead of "through what medium." Some alternatives include "by what means," "via what channel," "using what platform," and "through which avenue." All of these phrases convey the same idea but provide variety in writing or speech. These synonyms can be helpful in avoiding repetitive language and creating a more engaging conversation or written content. It is important to choose the right synonym based on context and audience to ensure effective communication.