Extensions are an integral part of our daily vocabulary, and there are various synonyms for this term. First and foremost, "additions" stands out as a synonym for extensions. Additions signify elements added to a pre-existing structure, just like extensions. Another replacement for the word extensions is "elaborations." Elaborations are additional details that enhance the content of a piece. Furthermore, "expansions" are a perfect synonym as they signify the expansion of an idea. Last but not least, "prolongations" are a synonym that refers to extending time or space of an object. All in all, extensions can be replaced with a plethora of synonyms, depending on the context.