气体扩散 qìtǐkuòsàn gaseous diffusion Origin Definitions Defs Strokes Stroke Words Sentences Sents 气体 氣體 qìtǐ noun gas gas; gaseous substance; a physical state of matter that has no fixed shape or volume扩散 擴散 kuòsàn diffusion (scientific) the movement of substances from an area of higher concentration to lower concentration until balanced