A group or member thereof which does not represent the largest group. The largest group is not necessarily the majority, which technically means a group representing over half of the total population. If the largest group is still less than half, they are the plurality.

Lately, a minority is also an oppressed/less-empowered group or member thereof, regardless of the actual size of the group. One can be a minority even if one is technically in the majority.

For example, there are about six million more women than men in the United States but women are still often considered a 'minority'.

Yes, this is an example of semantic drift, and is not what the word originally meant. Population statistics dated 1999 from the census.gov website.

Mi*nor"i*ty (?), n.; pl. Minorities (#). [Cf. F. minorit'e. See Minor, a. & n.]

1.

The state of being a minor, or under age.

2.

State of being less or small.

Sir T. Browne.

3.

The smaller number; -- opposed to majority; as, the minority must be ruled by the majority.

© Webster 1913.