Etymology: Middle English maiour, from Latin major, comparative of magnus great, large — more at much
Date: 15th century
1. greater in dignity, rank, importance, or interest <one of the major poets> 2. greater in number, quantity, or extent <the major part of his work> 3. having attained majority 4. a. notable or conspicuous in effect or scope ; considerable <a major improvement> b. prominent or significant in size, amount, or degree <earned some major cash> 5. involving grave risk ; serious <a major illness> 6. of or relating to a subject of academic study chosen as a field of specialization 7. a. having half steps between the third and fourth and the seventh and eighth degrees <major scale> b. based on a major scale <major key> c. equivalent to the distance between the keynote and another tone (except the fourth and fifth) of a major scale <major third> d. having a major third above the root <major triad> II. noun Date: 1616 1. a person who has attained majority 2. a. one that is superior in rank, importance, size, or performance <economic power of the oil majors> b. a major musical interval, scale, key, or mode 3. a commissioned officer in the army, air force, or marine corps ranking above a captain and below a lieutenant colonel 4. a. an academic subject chosen as a field of specialization b. a student specializing in such a field <a history major> 5. plural major league baseball — used with the 6. any of several high-level tournaments in professional golf III. intransitive verb Date: 1913 to pursue an academic major <majored in English>
New Collegiate Dictionary. 2001.