mi·nor / ˈmīnər/ • adj. 1. lesser in importance, seriousness, or significance: she requested a number of minor alterations. ∎  (of a surgical operation) comparatively simple and not life-threatening.2. Mus. (of a scale) having intervals of a semitone between the second and third degrees, and (usually) the fifth and sixth, and the seventh and eighth. Contrasted with major. ∎  (of an interval) characteristic of a minor scale and less by a semitone than the equivalent major interval.Compare with diminished. ∎  (of a key or mode) based on a minor scale, tending to produce a sad or pensive effect: Concerto in A minor.3. Brit., dated (following a surname in public schools) indicating the second or younger of two brothers or boys with the same family name: Smith minor.4. Logic (of a term) occurring as the subject of the conclusion of a categorical syllogism. ∎  (of a premise) containing the minor term in a categorical syllogism.• n. 1. a person under the age of full legal responsibility.2. Mus. a minor key, interval, or scale. ∎  (Minor) Bell-ringing a system of change-ringing using six bells.3. (the minors) the minor leagues in a particular professional sport, esp. baseball: he's been pitching in the minors for six years.4. a college student's subsidiary subject or area of concentration: a minor in American Indian studies.5. Logic a minor term or premise.6. Bridge short for minor suit.PHRASES: in a minor key (esp. of a literary work) understated.PHRASAL VERBS: minor in study or qualify in as a subsidiary subject at college or university.