Answer: diffusion

AnswerCrossword Clue
DIFFUSIONOsmosis, e.g.
diffusionThe action of spreading the light from a light source evenly so as to reduce glare and harsh shadows
diffusionThe spreading of something more widely
diffusionThe dissemination of elements of culture to another region or people
diffusionThe intermingling of substances by the natural movement of their particles
diffusionthe spread of ideas, disease, technology, etc.