The word "扩充" is formed by combining the character "扩", meaning to enlarge or expand, which itself derives from the hand radical "扌" indicating action and the component "广" suggesting breadth, with the character "充", meaning to fill or suffice, originating from elements depicting fullness. Together, "扩" conveys the action of expanding, while "充" contributes the sense of filling or completing, resulting in a compound that denotes extending or increasing something in scope or capacity.