1ma·jor 
/ˈmeɪʤɚ/ adjective
/ˈmeɪʤɚ/ adjective 1 a : very important
▪ a major poet/artist ▪ He's one of the major figures in 19th-century U.S. history. ▪ Researchers have announced a major advance/breakthrough in the treatment of cancer. ▪ major American cities ▪ a major event ▪ a question of major [=great] importance ▪ major rivers/roads ▪ She played a major role in the negotiations. ▪ a major earthquake ▪ a writer's major works ▪ No major changes are expected. ▪ The problems do not appear to be (very) major.
b always used before a noun : large in number, amount, or extent
▪ The grant covered a major part of the cost. ▪ Butter is one of the major ingredients in the recipe. ▪ The movie turned out to be a major disappointment. [=the movie was very disappointing] ▪ (informal) A car like that costs major money. [=a lot of money] 2 : very serious or bad
▪ None of his health problems are major. ▪ a major illness/disease ▪ He suffered a major heart attack. ▪ She's having major surgery. ▪ major depression ▪ a major accident 3 music a of a scale : having semitones between the third and fourth and the seventh and eighth notes
▪ a major scale ▪ the C-major scale [=the major scale that is in the key of C]
b : based on a major scale
▪ a major key — compare 1minor 3
▪ a major poet/artist ▪ He's one of the major figures in 19th-century U.S. history. ▪ Researchers have announced a major advance/breakthrough in the treatment of cancer. ▪ major American cities ▪ a major event ▪ a question of major [=great] importance ▪ major rivers/roads ▪ She played a major role in the negotiations. ▪ a major earthquake ▪ a writer's major works ▪ No major changes are expected. ▪ The problems do not appear to be (very) major.
b always used before a noun : large in number, amount, or extent
▪ The grant covered a major part of the cost. ▪ Butter is one of the major ingredients in the recipe. ▪ The movie turned out to be a major disappointment. [=the movie was very disappointing] ▪ (informal) A car like that costs major money. [=a lot of money]
▪ None of his health problems are major. ▪ a major illness/disease ▪ He suffered a major heart attack. ▪ She's having major surgery. ▪ major depression ▪ a major accident
▪ a major scale ▪ the C-major scale [=the major scale that is in the key of C]
b : based on a major scale
▪ a major key — compare 1minor 3
