adj., n., & v.
adj. 1 important, large, serious, significant (a major road; a major war; the major consideration must be their health). 2 (of an operation) serious or life-threatening. 3 Mus. a (of a scale) having intervals of a semitone between the third and fourth, and seventh and eighth degrees. b (of an interval) greater by a semitone than a minor interval (major third). c (of a key) based on a major scale, tending to produce a bright or joyful effect (D major). 4 of full age. 5 Brit. (appended to a surname, esp. in public schools) the elder of two brothers or the first to enter the school (Smith major). 6 Logic a (of a term) occurring in the predicate or conclusion of a syllogism. b (of a premiss) containing a major term.
n. 1 Mil. a an army officer next below lieutenant-colonel and above captain. b an officer in charge of a section of band instruments (drum major; pipe major). 2 a person of full age. 3 US a a student's special subject or course. b a student specializing in a specified subject (a philosophy major). 4 Logic a major term or premiss.
v.intr. (foll. by in) US study or qualify in a subject (majored in theology). major axis the axis of a conic, passing through its foci. major-general an officer next below a lieutenant-general. major league US a league of major importance in baseball etc. major part (often foll. by of) the majority. major piece Chess a rook or queen. major planet Jupiter, Saturn, Uranus, or Neptune. major prophet Isaiah, Jeremiah, Ezekiel, or Daniel. major suit Bridge spades or hearts. majorship n.
[ ME f. L, compar. of magnus great ]