adjective
    
    very important
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    b always used before a noun :large in number, amount, or extent
    
    
    
    
    
    
    
    
    
    very serious or bad
    
    
    
    
    
    
    
    
    
    
    
    
    
    music
    
    a of a scale :having semitones between the third and fourth and the seventh and eighth notes
    
    
    
    
    
    based on a major scale
    
    
    
    noun
    
    plural -jors
    
    [count] a military officer in the army, air force, or marines who ranks above a captain
    
    
    
    
    
    US
    
    the main subject studied by a college or university student
    
    
    
    
    
    a student who has a specified main subject of study
    
    
    
    
    
    the majors
    
    US informal :the major leagues of baseball
    
    
    
    verb
    
    -jors; -jored; -joring
    
    major in
    
    [phrasal verb]
    
    major in (something) US of a college or university student :to have (a specified subject) as your main subject of study
    
    
    
    major on
    
    [phrasal verb]
    
    major on (something) Brit :to pay special attention to (something)