The term "major parts" can be replaced with various synonyms depending on the context. For instance, in technical jargon, "major parts" could be exchanged for "essential components" or "critical elements". Likewise, in casual conversations, "major parts" might be substituted with "key pieces" or "vital segments". Similarly, "significant sections" and "primary constituents" can also be used as synonyms for "major parts". It is crucial to use appropriate synonyms to communicate clearly and effectively. Knowing the correct synonym for "major parts" can improve communication and convey your message concisely.