1. The act of pouring a fluid over something: The suffusion of water to saturate the plant helped it to regenerate itself after being dry for a long time.
2. The condition of being wet with a liquid: Jack spilled the milk and its suffusion spread over the surface of the table and dripped onto the floor.
3. A spreading out of a body fluid from a vessel into the surrounding tissues: Susan could see the suffusion of blood on her skin after falling down the steps and hurting her arm badly.