n.
Pronunciation: di- ' fyü-z ə r
Function: noun
Date: circa 1679
1 : one that diffuses: as a : a device (as a reflector) for distributing the light of a lamp evenly b : a screen (as of cloth or frosted glass) for softening lighting (as in photography) c : a device (as slats at different angles) for deflecting air from an outlet in various directions
2 : a device for reducing the velocity and increasing the static pressure of a fluid passing through a system