Definitions:
important, serious, or significant

(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

a student's principal subject or course

a major term or premise.

a goal.

specialize in (a particular subject) at college or university