Major is a versatile word with multiple meanings that can be described by different terms. It could be a noun referring to a course of study or a rank in the military, or an adjective indicating something important or significant. Some synonyms for the word major include significant, crucial, essential, important, and primary. Other related terms include principal, pivotal, paramount, fundamental, and key. When used as a noun, some alternatives for major are specialty, concentration, and subject. Using synonyms can help in avoiding redundancy and enriching one's vocabulary.