To spread over a large area; to cause to become widely known

फैलाना

English Usage: The artist was diffusing colors across the canvas.

Hindi Usage: कलाकार कैनवास पर रंग फैला रहा था।

The process of spreading or scattering something

फैलाव

English Usage: The diffusion of light creates beautiful patterns.

Hindi Usage: प्रकाश का फैलाव सुंदर आकृतियाँ बनाता है।