Definition of: effusion

(i·fy′zhən) noun
1. The act or process of pouring forth, or that which is poured forth.
2. An outpouring, as of fancy or sentiment: applied ironically to literary compositions.
3. Sentimental demonstration.
4. Pathol. The pouring out of the blood or other fluid, as into the cellular tissue.
5. Physics The flow of gases under pressure through openings in the container.