The term refers to any group that may be treated differently and unequally because of its physical, cultural, or other characteristics.

The answer is Minority.
the current definition of minority has been strayed really far away from the initial meaning. The actual meaning of minority is simply a certain group of people which number is less than half of the whole number.
But in real life application, the minorities do tend to be more likely to be discriminated against because they possess lesser social standing in society.