The word "加油" is formed through a vivid conceptual metaphor originating from the literal act of adding fuel. The first character, 加 (jiā), means "to add", and the second, 油 (yóu), means "oil" or "fuel". It visually evokes the historical image of manually pouring oil into a lamp to keep it burning brighter or adding fuel to a fire or engine to increase its power and momentum. This tangible action of providing essential sustenance to maintain or boost energy was metaphorically extended to the human spirit, transforming into a universal exhortation to persevere, put in more effort, and bolster one's vigor, as if stoking an internal fire.