major

adjective

• 1 [attributive] important, serious, or significant:the use of drugs is a major problem
• greater or more important; main:he got the major share of the spoils

• 2 Music (of a scale) having intervals of a semitone between the third and fourth, and seventh and eighth degrees. Contrasted with minor.
• (of an interval) equivalent to that between the tonic and another note of a major scale, and greater by a semitone than the corresponding minor interval: C to E is a major third
• [postpositive] (of a key) based on a major scale, tending to produce a bright or joyful effect:Prelude in G Major

• 3British dated (appended to a surname in public schools) indicating the elder of two brothers.

• 4 Logic (of a term) occurring as the predicate in the conclusion of a categorical syllogism.
• (of a premise) containing the major term in a categorical syllogism.

noun

• 1a rank of officer in the army and the US air force, above captain and below lieutenant colonel.

  [shortening of sergeant major, formerly a high rank]
• [with modifier] an officer in charge of a section of band instruments:a trumpet major

• 2 Music a major key, interval, or scale.
• Bell-ringing a system of change-ringing using eight bells.

• 3a 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 [with modifier]:the oil majors had a profit bonanza

• 4North American a student’s principal subject or course: many students would ignore courses outside their major
• [often with modifier] a student specializing in a specified subject:a math major

• 5 Logic a major term or premise.

• 6 Bridgeshort for major suit.South was anxious to mention his four-card major and bid one spade

• 7 Australian Rules a goal.

verb

• specialize in (a particular subject) at college or university:I was trying to decide if I should major in drama or English