characteristic, feature - a prominent aspect of something; "the map showed roads and other features"; "generosity is one of his best characteristics"

side - an aspect of something (as contrasted with some other implied aspect); "he was on the heavy side"; "he is on the purchasing side of the business"; "it brought out his better side"

sector, sphere - a particular aspect of life or activity; "he was helpless in an important sector of his life"

surface - a superficial aspect as opposed to the real nature of something; "it was not what it appeared to be on the surface"

subfigure - a figure that is a part of another figure