singular noun. If you talk about a minority of people or things in a larger group, you are referring to a number of them that forms less than half of the larger group, usually much less than half.

What means sizeable?

: fairly large : considerable a sizable donation.

What it means to be a minority?

The definition of a minority is a group of people that differ in some way from the majority of the population, or any part of a whole that is smaller than the other parts. ... A person from a non-Caucasian race is an example of a minority.