Minor  —adj. 1 lesser or comparatively small in size or importance (minor poet). 2 mus. A (of a scale) having intervals of a semitone above its second, fifth, and seventh notes. B (of an interval) less by a semitone than a major interval. C (of a key) based on a minor scale. —n. 1 person under full legal age. 2 us student's subsidiary subject or course. —v. (foll. By in) us study (a subject) as a subsidiary. [latin, = less]