minor

Legal term for those under the age of majority, which varies from country to country but is usually between 18 and 21. In the USA (from 1971 for voting, and in some states for nearly all other purposes) and certain European countries (in Britain since 1970) the age of majority is 18.

Most civic and legal rights and duties only accrue at the age of majority: for example, the rights to vote, to make a will, and (usually) to make a fully binding contract, and the duty to act as a juror.

minor

One of the two predominant scales (the other being major) of the tonal system. There are three forms of the minor scale: the harmonic minor, the melodic minor, and the less commonly used natural minor.