- Any device or surface that scatters light or sound from a source.
- A circular, square, or rectangular air distribution outlet, generally located in the ceiling, and comprised of deflecting members to discharge supply air in various directions.
- A device utilized to disperse light or sound. Used, for instance, to guide the sound emanating from a horn speaker. Also spelled diffusor.
- noun tracing paper or some other transparent material, fixed over a light to make it less bright and harsh