important, serious, or significant

the use of drugs is a major problem

(of a scale) having intervals of a semitone between the third and fourth, and seventh and eighth degrees

(appended to a surname in public schools) indicating the elder of two brothers

(of a term) occurring as the predicate in the conclusion of a categorical syllogism

a rank of officer in the army and the US air force, above captain and below lieutenant colonel

a major key, interval, or scale

a major organization or competition

the majors have swept up the smaller independent companies in licensing deals

it's not unreasonable to believe someone can win all four majors

the oil majors had a profit bonanza

a student's principal subject or course

many students would ignore courses outside their major

a major term or premise

South was anxious to mention his four-card major and bid one spade

a goal

specialize in (a particular subject) at college or university

I was trying to decide if I should major in drama or English